Adam, you will have bent valves, so the cams do need to come out. Simply undo the u-shaped caps little by little and evenly across the length of the camshaft. Cam gears do not need to come off. Once the head is off and cams out, pour fuel/turps or other thin liquid to see where your leak is, if its not obvious by visual inspection. When you know the valves that are bent, mark them so the cylinder head guy/mechanic will know which valves and guides to change.
I have a valve removal tool you can borrow if you want to remove the other valves also (and/or remove the bent ones and replace yourself), and clean the carbon build up from them.
Or bring the whole head to me, I can remove the cams, and I'll see what can be done to tidy up/fix the head/valves (at whatever cost). I could remove the cams, identify the bent valves, check those guides, get new valves, get head faced (no porting) and possible valve guide replace, remove and clean all remaining valves, insert all valves, seat them in place, reinstall cams and torque caps accordingly. I've disassembled many, many heads over the years.
EDIT: I'm in Perth from Friday to Monday, so unavailable then.