Hi,
I disagree... Myself being a total newbie, i was able to disassemble, diagnose and rebuild my truck's engine with the help of the guys from this forum and the Nissan manual... I see many other posibilities for mistakes/fu**-ups/risks while removing and reinstalling the head and everything that such tasks requires than flattening it with this procedure.
I think that someone that cannot do this safely and reliably, should not try to fix his engine at all...!
Thats my humble opinion, of course...