Fast edit of Excel CSV format file and save to specific folder VBA

To get you started, you have a number of unqualified references within your code. This is particularly puzzling to me since you declare and pass worksheet objects, but you never use this object when determining a reference. For example:

Private Sub changeProperties(WS As Worksheet)

    Dim tableRng As Range
    Dim columnsToHide As Range
    Dim heatherFormat As Range

    Set heatherFormat = Range(Cells(1, 1), Cells(1, Columns.Count).End(xlToLeft)).Columns
    Set tableRng = Range("A2").CurrentRegion
    Set WS = ActiveSheet

This bit of code is a prime example for what I am referring to, and is a good learning opportunity as well. Let's refactor it together.

We will start with the sub declaration. As Mat's Mug will likely point out, you require 'WS as Worksheet' but this declaration is implicitly ByRef which means the object passed will be modified by any later actions on that object. To me, it looks like you are trying to use a Sub here to return a value (which is the purpose of a function). You have two options:

Private Function changeProperties() as Worksheet

And then we could do:

Set changeProperties = Activesheet

Or you could explicitly define the parameter as ByRef

Private Sub changeProperties(ByRef as Worksheet)

Neither of these changes will change the performance of your code, but it will make your code easier to read and understand, and it will start teaching you some coding habits that will be important later. Now, let's tackle that pesky ActiveSheet. I must say, there is no habit that must be broken sooner than Select, Activate, ActiveSheet, ActiveWorkbook, and Selection.

There's good reason why this is a bad habit. First, it makes your code unreliable. While the ActiveSheet could be the correct sheet, we have no way of absolutely guaranteeing. For example:

Sub Foo()
    ThisWorkbook.Sheets("bar").Activate

    ActiveWorksheet.Name = "baz"

End Sub

Nine times out of ten, this procedure will do exactly as we expect it to. It will find the "bar" worksheet within the workbook running the code, and then rename that sheet to "baz". What would happen though if we paused our code after Activating the sheet (perhaps for debugging?) and then a different sheet was activated. Now we have a bug.

This is easy to overcome:

Sub Foo()
    Dim NameChangeTarget as Worksheet

    Set NameChangeTarget = ThisWorkbook.Sheets("bar")

    NameChangeTarget.Name = "baz"

End Sub

Now, we can change sheets all we want but the correct sheet will be modified. This is a prime example of why we must always qualify our ranges. There will be some circumstances where ActiveSheet may be justified. The only instance I have had this happen with is when I am detailing into PivotTables, and getting the output sheet. Even then though, I try to avoid this practice if I have the time.

Next, naming conventions within your code. Overall, you are on the right track, but lets look at a couple areas where you could improve.

WS as Worksheet

This is very common, and I made the same error in naming when I first started off. For a while, it will be unlikely that you have any issues with this. There will come a point though where you are debugging your code, and you have multiple Worksheet variables, and WS just doesnt tell you what you need. Consider useful names that tell you something about what the variable contains such as these:

FormatTarget ' Tells us this is the worksheet being targeted for reformatting
DataOutput   ' Tells us that this is where the data is, and it is an output sheet
OutputDataNeedsFormatting ' This name sucks, but it does the same job as both names above

I am certainly not an expert on naming conventions, so find what works for you. Definitely be mindful of what your names tell your 'reader' though.

The other point worth noting here is how you have names that are inconsistent:

tableRng ' Tells us that it is a range despite it being declared as a range
columnsToHide ' Pretty good name, we know these are the columns being hidden

' On the one hand, I have no idea what 'heather' is. Do you mean header? 
' On the other hand, by the 'Format' I assume that this is formatting, but it is a range.
heatherFormat

Lastly, lets look at this particularly troubling line:

Set heatherFormat = Range(Cells(1,1), Cells(1, Columns.Count).End(xlToLeft)).Columns

   ' First, the name is somewhat confusing, as noted before. We then are using
   ' an implicit call to 'ActiveSheet' since 'Range()' is unqualified
   ' next, we are setting a range based upon two more unqualified 'Cells' references, 
   ' and we are resizing this range to the left until we find data. After all of this, 
   ' we are retrieving the columns and then putting it back into heatherFormat.

Consider something like this instead:

' You can always pass in the sheet as a variable, and get the specific
' sheet from the person running the code when they first call the routine.
With ThisWorkbook.Sheets("SheetName")
' Or With PassedInVariable
    Set headerFormat = .Range(.Cells(1, 1), .Cells(1, .Columns.Count).End(xlToLeft)).Columns
End With

There isn't a big difference here. I have taken an extra step to ensure I have qualified the object I am working with, and I use a With block to do this. As a result, all I need to do is put a period before each object I need to qualify and voila! On bigger projects, With blocks can increase performance, and they make your code much easier to read. Above all else, they get rid of the pesky implicit ActiveSheet calls.

I'll insert a plug for RubberDuck here. Mat's Mug and his team have come up with a great tool that can make this process much easier on you. RubberDuck has a 'Code Inspection' feature that finds all this stuff for you, helps you fix it, and oftentimes tells you why it is wrong. Check it out if you have a chance.

Once you have refactored this code to remove this beginner stuff, you may be interested in using the Split() function, and Variant arrays in order to accomplish the original splitting of your data.

Good luck!