Replace Semicolons with Commas in CSV Salesforce Data Imports

Use Notepad or set the default list separator symbol in the Regional Settings 

Option 1: Use Notepad or WordPad to update the list separator to a comma  

1. Right click on the file. Select Open with Notepad or Wordpad.
2. Select the Edit menu and then select Replace.
3. Enter a semicolon ';' into the Find what box.
4. Enter a comma ',' into the Replace with box.
5. Click the Replace all button.
6. Close the Replace window.
7. Save the file as a .csv.

Option 2: If you're on a Windows computer, you can skip using Notepad and instead set the default list separator symbol in the Regional Settings to a comma

1. Select the Start menu. 
2. Click on the Control panel. 
3. Select  "Clock and Region".
4. Click "Change date, time or number formats."
5. Select "Additional settings..."
6. On the List Separator: change to Comma (,) and select OK.
7. If you are prompted to restart the computer, do so.

Note: Do not open the CSV file after the update is done. This will revert the list separator back to semi-colon (;).

Note : For Mac Users: On macOS, use TextEdit or Numbers. Open the CSV in TextEdit, use Edit > Find > Find & Replace to substitute semicolons with commas, then save as Plain Text (.csv).