When you make a change to a Google Docs document, a copy of the previous version will be saved. This allows you to roll back the changes, but you can hide or delete the version history if you prefer. Here’s how it is:
Log in to your Google Account and click on the “Documents” tab to access your files.
Click the file you want to delete the revision history for. The file will open in a new edit window.
In the document window, click the “File” button (not in the main browser “File” option).
Select “Copy” and click “OK.” The new copy will be opened in the new browser tab.
Go back to your Google Docs homepage. Mouse over the original file and click the Actions button. To remove the file, click “Move to Trash.”
Click the “Actions” button on the copied file. Press the “Rename” button and remove the “Copy of” text from the title.
Now you have a complete copy of the file with the same title as the original file.
When you access the revision history of this copied file, it will show only the copy creation and none of the revisions made to the original file.