I took out both brake pads so I could compress the piston a bit. (The caliper is disconnect off the car) I can put the pad that goes against the piston in fine, but the other pad is being a PITA to put back in. I cant seem to push it down far enough for the side tabs to side into place. Am I doing something wrong, or is this normal?

 

Maybe brake dust has built up and made it difficult to get into the slots, maybe the piston isn't pushed back into the caliper far enough to let you put both brake pads in and fit it over the rotor. either is possible.
I usually grab an old brake pad and a C clamp and tighten it down until the piston is compressed all the way. Then slide the pads on and call it a day.

 

I got it. I took the caliper off its mounting bracket, and placed the mounting bracket on the rotor, with the pads. Then I just slid the caliper onto the mounting bracket. It was very easy to do, and took about 2 mins.

I used this: http://http://www.installuniversity....ds_mwarren.htm