Part One: New Door Hinges
I also installed new doors from LMC before I took the truck in for paint because mine were wavy and had sloppy hinges. The hinges have a brass bushing that can be replaced to tighten them back up, which you can get as a kit from LMC. To get the doors off, all you have to do is remove the spring and then knock out the pin. You will need a spring-removal tool like the one pictured to do the job right. You can pry it out with a big screwdriver, but that is way unsafe and putting it back in will be next to impossible without driving yourself crazy. You can get the tool from a lot of places; I got mine from Eastwood Co. for 20 bucks.