BMW Repair: Cylinder Head Removal, head gasket, gasket

Question
Hi there
I have a 1987 South African made E30 333i with the same motor that was in the 633i.I recently discovered that the head had previously been skimmed due to an overheating problem the car had.I was told that the head gasket now in place is an UNDERSIZE gasket and will need to be replaced with an OVERSIZED head gasket.What I would like to know is how difficult a job is it to remove the head and replace the gasket,is it something that should be left to a professional,or is it something I myself can do?
Thanks!
Morgan

Answer
To replace a head gasket is quite a job.If you are not an experianced mechanic I would farm it out,as it does get involved.
Why do you have to replace It?As far as under and over sized,If alot was removed when machining it is important to know how much was removed.AS the valves will hit as there is no extra clearance