cq exaust manifold advice

[irish80sport]

i need to get the gasket on the exaust manifold replaced on my 86 cq. i brought it to my mechanic after getting him all the gaskets, but when he took a closer look 4 of the 5 of them had already been replaced, just leaving the last and hardest apperantly to be done, a job which my man dosent want to take on as it looks like the engine has to come out!!! is there a simple way to get the job done? any help would be much appreciated as the 5 pot just sounds like a tractor at the moment