What I do is stick a small screwdriver in the rocker switch on the joystick for the header raise and go back and check for your leak. This keeps the oil flowing thru the block. Use a 5/8 wrench to unscrew the valve and if it just wants to unscrew on the end use a visegrip. All the parts you will need will come in a kit. A little oil will come out so have all your tools and parts ready. Easy job.