Alright mate......

I did a full rebuild of my calipers last year using a rebuild kit from a company called 'Big Red'. It cost me about £20.00 and was really east to do, just strip the entire caliper down, clean it up and reassemble with new seals etc..
You've just got to make sure the pistons aren't pitted to death and are totally clean when putting them back together!
Hope this helps!