Does anybody know of any documentation on editing an extension that already has been activated? Thanks

This is not possible and/or recommended. If you own the extension, then make modifications locally and push up your changes. If it is third-party, then you will need to write code that extends or modifies it.

Awesome thanks Yes I would like to modify my own extension. So i cold just fetch it make changes and then deploy?

Sure. Ideally you should have a copy saved locally or in version control, but yes you can fetch your source from the server, make changes, and then push it back up.

Awesome thanks a ton!