From the Team Timesheets option on the left menu, select a specific timesheet.
On the top left of the window that pops up, choose History
Here you can see a record of all changes to this specific time sheet, which user performed the change, what time and date it was changed, and what changes were made.
Download Timesheet History
You can download a copy of the specific timesheet as a CSV file. To do so, select the Options button on the upper right, and click on Download as CSV.
Choose where on your computer to save the file. You may now open this in your chosen spreadsheet software.