To replace the clutch you will need to split the tractor behind the engine. Tractor splitting has been covered a lot on YT so I'm not going to cover it. I would suggest that you get a service manual before starting. I have a used copy for $25.
When you have the tractor apart you will need to remove the pressure plate, clutch disk, and flywheel. To change and or inspect the pto clutch disc you will need to further disassemble the pressure plate. The flywheel will need to be inspected to insure that it is in good condition.
While you have it apart inspect the throw out bearing and transmission seal for leaks. Replace the throw out bearing, might as welldo it while everything is apart.
To put back together a clutch alignment tool will be needed. I have used parts to help if you need them. 802---------