Its very specialist, if assembled incorrectly they will spontaneously combust taking your car, wife and kids and house and parents house with it......
Or you can send them to me or Jonny who will charge like a wounded rhino.......
Only joking...Its a sort of job that needs some respect as it is of course brakes but if you got shown how to do one or two you'd be able to service pretty much any rear caliper going forward.
If you're still in Southport way pop over if you can catch me in and I'll do one side and you can do the other with me looking over your shoulder. Repair kits from Brakes International are about £10 a corner - no charge from me