hi, ive got a 300tdi of which the head gasket blew so i took the head off last weekend planning to get it skimmed and put back together! wrong- on closer inspection two of the pistons are a bit worse for wear, anyway cutting a long story short ive brought another engine and was just wondering if anyone could give me a bit of advice on swapping them over as i have never removed an engine from a vehicle before. any advice would be greatly appreciated