think you need a 7mm hex bit for these,behind the two plastic plugs,the whole caliper slides on these on a single acting piston so lube them up with copaslip and the pistons should press back into the caliper,a `g` cramp would do for this and apply copaslip to all mating surfaces on re assembly,good luck
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.