I've worked with the plastic welds before. I was recovering some door panels on a 95 Civic. All I did was take a soldering iron to the plastic spot welds, and once it starts to get soft, just pop them through. If you have an extra junk door panel that you're working with, I would cut off some of the plastic from it to use when you put the panel back together. Just do it as if you're soldering plastic. It's not that bad.