2016 Prius Two Eco - rear brakes, what am I doing wrong

So, I did do a bit of digging first, but I'm wondering if I'm doing something wrong. I've done more than my share of disc brake replacements in the past, and even last year. Never did it on a Prius or any hybrid though.

I've got about 80k miles on my Prius, and I was told that the rear brakes are very low. Of course, the dealer would love to do it, and insists that the rotors also need to be changed. I can only imagine what they'll charge. I figured I might at least attempt to inspect it myself.

I am aware of the weird cross-like thing that I'll have to rotate back in if I put new pads on, but at this point, I'm just looking to inspect, and see if I can get the caliper off.

This is what I did:

1. Opened car with fob, and opened hood
2. Disconnected negative terminal of battery
3. Loosened lugs
4. Jacked up car
5. Removed lugs and tire
6. Realized I couldn't even turn the hub, thus went back and released the parking brake (it's a mechanical one)
7. Now could turn the hub via hand on the studs, but there's some resistance
8. Removed caliper bolts

This is where it gets weird. I completely removed the top bolt, but left the lower on, but very loose (could easily turn with fingers), figuring I could just pivot the caliper without fully removing it.

The caliper would barely budge. Couldn't do anything with hand, and using large flat-head screwdriver as a pry, I maybe got it to move a hair, at best.

Are there any extra steps I've missed? I'd really like to give it a try again this weekend, probably on Sunday.


As a side note - for that part on the caliper that I have to rotate back in, will a typical needle-nose be strong enough to do it, or should I get a particularly heavy duty one because it needs a lot of force? I've read in a few places that the specific tool to rotate it back into place is awkward.

EDIT: while I'm on this, are the typical semi-metallic pads the norm on a 4th gen Prius, or do I need to get something different?

 

That looks straightforward enough, but it's the rear brakes I'm working with, and there's some extra considerations like the rotating piston retraction, the car possibly attempting to push the rear brakes even when off (hence why I assume the battery disconnect is required), and so on.

Just wondering if I had missed something in my steps.