2 bolts hold the wheel cylinder in and one hydraulic line. I suggest you soak the hyd line fitting with PB Blaster
for a day or two prior to loosening that fitting with a FLARE NUT WRENCH. Sorry, I don't know the size, but a flare nut wrench will prevent stripping that soft fitting nut.
I've also found that when loosening a brake line, use a sharp snappy jerk rather than a steady hard pull to break it loose.
You can also buy a very inexpensive rebuild kit for the wheel cylinder and never even remove the old one. Still have to bleed it though. I've worked on some rusty POS in my day and thrown the rebuild kit in when they are galled up and stubborn.
Wheel cylinders are so dirt cheap, you really should just replace it.