I just tackled this wonderful task and thought I might be able to help the next person. The soldering iron trick did work well for both removing the metal posts from the old plastic and reattaching the metal posts to the new plastic. I first had to make the holes in the new plastic bigger. I tried a 7/32 drill bit and then ended up at 1/4 inch which was ideal. The plastics did not get damaged by carefully drilling the holes - it may be best to do the two step process - making them just a little bigger each time.

Also, don't bother trying to unflare the end of the post, reinsert into the plastic and then flare (or crimp) it back again. I saw that suggested somewhere. That did not work well, but the solder iron insertion technique worked fantastic. Here is a video I found that shows how it's done. Just apply somewhat firm pressure on the plastic and the post will pop right through the plastic. I was just doing the top decorative plastic and it still worked fine. Not as painful as I expected. Good luck to all!