I was just editing the post with a bit more detail when you asked that one.. It's not hard to do. Unscrew the knob, remove the "C" clip & the plate lifts off. Shouldn't be more than 5 minutes.
Two things to be aware of though. The "C" clip and locking spring can both join all the lost socks in the 4th dimension when they launch.
If you would like I can replace the spring and fix up the lever for you. I'm thinking $10.00 & you pick up shipping both ways.
PM me if you would like.