(Firefox) How can I permanently delete my bookmarks so that the "Restore" cannot restore them?

https://support.mozilla.org/en-US/questions/807309

In Firefox 4, I have already deleted some bookmarks from the bookmarks menu, but the "Restore" option still allows anyone to go and find my personal information. How can I delete the information available to the "Restore" button?

Chosen solution

by the-edmeister

http://support.mozilla.com/en-us/kb/Profiles#How_to_find_your_profile

Open the \bookmarkbackups\ folder in your Profile folder and delete all the JSON bookmark backup files with dates prior to the date when you deleted those bookmarks.