Edward, you need a peg-spanner to remove the bearing retainer. Drill out the punch marks first, or you'll strip the thread.
Ugly screw should come out easy once you remove the nut, the fork tab is threaded too, so if you don't undo the nut, you won't get it out.
If that screw (or any screw) is rusted/corroded in, make a 50/50 mix of Auto Transmission Fluid (ATF) and Acetone, and soak the screw for a day or two, and it'll come out. Mangled "cheese head" screws need to have their heads drilled off.
Use a 6 or 7mm drill bit to drill down until the remains of the heads pop off, remove the cover, and then wind the remains of the screws with a pair of Vice-Grip pliers.
Have fun, don't give up, it's like "Fire and Movement", you just need to keep moving forward. Cheers, Terry.