Revert Site lets you get the old Facebook design / layout back. It makes Facebook think you are using an old out of date browser, so it shows you the old design instead of the new one, and also prevents Facebook from switching you back to the new design (until they completely remove the old design, which may be a few months time or longer)
Revert Site is very quick to install, and very easy to use, it just has a single option, that is turned on by default, so you can just install it and not have to configure anything. However if you wish to temporarily disable Revert Site, you can easily do so by clicking the extension icon, in the browser's extensions toolbar, then un-ticking the "Switch back to the old Facebook design" checkbox. To turn it back on, just re-tick the checkbox.
If you can't find the Revert Site (R) button in your extension's toolbar, it may be hidden behind the "Wireframe cube" button, so click that and see if its behind there.
Revert Site won't work if you open Facebook via the Speed Dial button on Opera's new tab page. If you do open Facebook via the speed dial button, quickly click in the URL/Address bar and press return, then Revert Site should run ok. Otherwise if you open Facebook via a bookmark or by typing the URL in (fb.com works) then Revert Site should run ok too.
Please also note Revert Site can't revert personal profile pages, they will load in the mobile web format. Im looking into fixing this, but not had much luck yet.
If you do get switched to the mobile site (m.facebook.com) try reloading the page, and seeing if that switches you back to desktop mode. If it doesn't type fb.com into the browser's URL/Address bar to get the desktop version of the facebook website back.
If you have any problems with video and voice Messaging on the Facebook site, with this extension installed, again using the auxiliary Facebook messaging website, messenger.com to do your Facebook video and voice calls should work fine.
- This extension can access your data on some websites.