G'day doing a head gasket change on a 95 xg longreach. Have done everything including releasing chain tensioner . The only things left are the bolt on the top left side of the head ( when looking at the motor front on). And releasing head bolts. My question is if i remove the top left hand bolt. Can i remove & replace the tensioner that the bolt holds . Or will i have to remove entire timing cover.
Thanks in advance.

U have to remove the whole front timing cover. Its a fairly big job

You only really need to replace that guide if it's broken - and that usually happens if you're not careful putting the head back onto the block.