Replacing Intake Manifold Gasket

[xp_wannabe]

My AU2 XR6 Ute (VCT) has developed a rough idle and a bad miss just off idel / under load. Clears out fine with a few revs. It is also hard to start when cold.

I have replaced coil, leads and plugs (leads and plugs twice thinking they were faulty) and had the injectors cleaned, to no avail.

I am thinking it is the intake manifold gasket, as I have read on here that it is quite common.

I have sprayed aerostart all around the intake manifold with the engine idling, but didn't notice any change. Could the gasket still be faulty?

Is there a good thread on here showing how to replace the gasket? Is it a big job?

Thanks, Mark