Traditional route: Go here and start unchecking. Time consuming, but does the job.
Pricey route: Rename your account to something like 1122yydd6677. Let it wipe your flist when it asks if you want it to. Rename back to ~beadedbracelet. Total cost: $10 USD.
What I do to mass add/remove tons of journals (usually my own haha): This will seem way more involved than option one, and there are more steps than option one, but it's faster for big lists like your flist. I promise!
--> Copy your list of friends. Paste it in Notepad and run a replace all (CTRL+H) on , and replace it with <br>. Remember to hit REPLACE ALL and not REPLACE or you'll be doing a lot of clicking.
--> Copy this new version and paste it here. Hit "test code" and copy that list.
--> Go here. Paste the list into INPUT BOX and type Friend remove (with a space at the end of it) into the box under "Add this prefix to each line of text." Hit "Add Prefix and/or Suffix."
--> Paste your completed list into the admin console, hit EXECUTE, and you're done.