I installed new O-rings in the AMP regulators in my Maverick and found a simple way to make it easier to install those tiny 2mm x 1mm O-rings. I threaded the adjusting screw topside down into the reg body so I had 2 hands free to get the O-ring over the end of the screw. I suppose another idea would be to get a nut with the same threads and make a little fixture to clamp in a vise.