I tried using really thin philips and hammering it one way (tried both ways) loosen them up but didn't try to use too much force as to not damage them.Just get a set of needle nose pliers open em so the tips are in the holes and turn em
It will just be either a thread or a T shaped tounge holding the cap on
If your pads are scraping you may need to replace/machine the discs aswell
If your tecnical prowess dosent extend to working out how to remove a wheel cap I wonder wether DIY brake work is a very good idea...No offence intended but the brakes are probably the most important item on the car
And if you start and make a mess of the job you wont be able to drive to the brake shop to get it sorted!
Just a thought ,but good luck all the same
Make sure to open the brake reservoir cap when doing so, wouldn't want that blowing off.As far as the brake job goes, use a C-clamp to push the pistons back into the bores and just make sure you properly grease the backs of the pads. Be sure the pairs of bolts on the calipers are nice and tight.