I just removed both the side frames on my 110. I was going to get the B pillar repair, but the sill frame is pretty rusty, excessive scaling in some of the seams. I could blast it and do a full rebuild on it, but for about $700 I am replacing the both side frames with brand new genuine ones. Going to have the e-coat removed and galvanize them. This way, the entire section is brand new and won't rust.
It was a toss up between repair or new, and with that cost to get completely new frames, it's hard to beat.
For the repair sections, you would have to cut away the bottom of the B pillar, grind off the weld on the sill and weld those new ones in, back of the pillar first, then the front. clean it up, fill it and paint. It's a lot of work either way.