All you can really do is remove the head, fix the leak and put the head back on. Well, technically you also put some nasty stop leak stuff in it, but the risk to reward reatio is poor.
I've removed a CA head with both manfiolds attached, but in the end I questioned if it saved me any time. My issue was more damaged exhaust studs stopped me getting the manifold off to change a head gasket.
As an aside, I only just remembered this thread because I am only just now sending all my gear off to be built 0_0
