After installing the script in your grease environment, and enabling it (you should disable it after you’re done, as it messes with facebook dialogs), head to your friends edit page (https://facebook.com/friends/edit), and you should see Fast Remove buttons next to every active friend’s picture. The edit friends page of facebook only displays a handfull of friends, but scrolling to the bottom adds another handfull to the page. You can put some adequately heavy object on your Page Down keyboard button, and leave it be until all friends are listed.
Now the first thing to do, is delete all your inactive friends (people who have disabled their facebook accounts). 90% of them never get back to facebook, and those who do, can go ahead and add you again. From the TamperMonkey (or equivalent) menu, click on FacebookDeleteX – Remove Inactive submenu. A confirmation box will appear, saying how many inactive friends found, and if you’re sure to delete them all. After clicking yes, all deletions are queued and another dialog gives you some information.
At this step, you should wait (or you can start doing the fast removal – next step). Because each removal requires 4 steps (requests to be made by the script), each one of them takes some time to accomplish. Closing the page will cancel them. If you’re removing 1000 inactive friends, you should wait at least 1000×3 seconds (or an hour). You can always check your number of friends before starting this, and check it again in another window and see when it reaches the desired amount (total_number – inactive_number), then close this window.
The final step, is manual fast-removal of your friends. In this step, you have to click on each Fast Remove button, next to people who you don’t want anymore. Don’t spend too much time deciding if something belongs or not, just press Fast Remove. Later you can add them again easily.
Every time you press Fast Remove, it takes a second or so for the requests to be handled and for the button to disappear (if you’ve a lot of requests queued from previous step, it can take a lot. Just click them once and proceed to the next one, or open another window and do this there) . Right after that, a dialog box pops up informing you that the friend was removed. This script will automatically close these dialogs once every second.
If anything seemed not to work with the script, don’t hesitate to contact me for a fix. Happy facebooking.
P.S this script takes 60% CPU on a MacBook Pro Retina (which is equivalent of 4 regular PCs).