I definately need to clean up the SEL from the scratches I put to it before getting my dremel. One side of the SEL is too thick so you have to grind it down in the middle. It was only at the end when I truly figured that the problem was from the middle to the bottom of it. I grinded that further to get it to fit better. It took me longer to grind it because I have the rechargable battery powered Dremel.
It took me two charges to full get it good. I still needed to use my bent spring bars to even get it to fit. I took a 22mm spring bar from one of my invicta watches and bent it at the left and right sized. I placed them into the hole and rotated them to face the case.
Forget sand paper and a file to get it down, you need something high speed to get a smooth and even grind down.
as for resizing it...lt was like the others said, a pain in the butt. I had to push the hole deep as possible until there was play between the links when I used my watch screw drivers to pry them open and see how dirty they are from the factory. One of the links had a piece that was some how melted into a hook like piece. It was weird. You coulding take it off the middle link.
Anyways that's how I did it