How much work is this for someone who knows fab work?
how much work is it? Not much. A sawzall and a few hours and they’ll be out. Very few people put inner wells back in, as it’s not that big of a deal. The one biggest problem is the battery. You can move it lower down off of the frame, or move it under the bed. If you use an optima you can mount it sideways which makes it easier if you ever need a jump, just run the jumper cables through the wheel well to connect.
Is removing your fenders something you are thinking of doing? Im guessing you are doing research so you can. It’s not hard, if you have some mechanical skills, and some common sense.
Most people get rid of the ABS pump and electrical for it, meaning one less thing to relocate and or make a bracket for once the inner fender is gone.