I would also say I broke about 6 clips on the first door I put back on, but it is still sturdy and sits just as flush as before.
I found the best strategy is to work your way around the door and line up pin by pin with the hole and just keep going in circles around the door until you feel like they are all in. You're not going to die if you break a couple, like i said I broke about 6 on one door and it still is fine.
But I do realize some people really care that all pins are back in, and it will bother the heck out of them if one breaks.
When you're taking the door off, you're going to make some loud noises that will scare the heck out of you. I used these to take the door off:
My door speakers took Metra 72-6514. I got these at best buy.
The center channel takes Metra 71-039C. I was told you can only get this at Crutchfield. I don't know if that is true, but it was the only place I could find it.
*Note that I have no idea if the adapters are the same for the focals. I used these for my Infinity's
I spliced the tweeters like everyone else did. I cant remember the size of the connectors, but just take one of your adapters to autozone or somewhere and just match the size of the connectors. I put the tweeters in like others with Infinity's. Use 3M double sided tape (the width is coincidentally almost perfect) and wrap it wroudn twice. Then just jam it in the slot (thats what she said).
If you go with the Inifinity for the rear door speakers, you have to use the supplied mounting bracket and make the mounting holes a little bit bigger with a 3/32 drill bit. You're also going to need a drill to mount it. All of my screwdrivers were stripping the screws.