@ Stevevee23,
Obviously, you don't know a thing about brake maintenance at all, nothing to be ashamed over at all, the problem start when you combine it with dumbassness, much more seen in the corsa-tuning scene, so one good piece of advice:
You can do it yourself, but first have somebody around who knows what he is doing, to assist you so you can learn.
If you get it wrong the first time doing it yourself, you might end up with no brakes at all, when you really need them.
Also when a hammer and screwdriver are the only tools you own, leave it to an expert.
The rear callipers need a special tool to retain, because you need to turn the pistons while pushing in. This is due to the handbrake system.
The locking pins are one way direction in and out!! and as said they have a splitting pin.
Also don't forget to clean the guiding bosses for the brake pads.
Also when you retain the calliper pistons, be sure that your brakefluidcontainer isn't up to max level, or elsewise you will spill it all over your front suspension. And brakefluid and carpaint don't go well together.