Is it hard to change Valves? I was wondering if I can just keep the engine at TDC just lift the head up and using a valve spring compressor, just remove the valves and change them over one at a time and just put the head back on. Would that be fine to do? or is there something more complicated involved?

I'm going to switch over to high compression valves. Also is it a good idea to change the piston rings when I have the head off as well?