My serious advice is don't bother, get a new set.
I did mine a few years ago, new seals etc all was well, but 2 years later back to sticking, mostly down to the crappy piston material ford used.
I just weighed up all the aggro car off road etc etc, new cost £45 each just wasn't worth the aggro to me, but as above says just a little brake fluid will do it, try to keep as square as poss when putting in.
tabetha