I just repaired mine using the repair kit, Holly 12-807, you can do it where it sits if it is leaking without removing it. A diaphram and two springs is all it is, as the above photo shows 4 screws, remove them and replace the spring and diaphram, shouldn't have to check your fuel pressure as long as you don't miscount or adjust the turns on the regulator. FWIW, after i changed mine my rig ran just fine for about 10 minutes then died lack of fuel, being I had just replaced my fuel pump and repair the bad diaphram in the regulator I was stumped. The fuel pump working no fuel at carb, aha, not enough gas (only 3 gallons and I cleaned the entire line all the way to carb using new gas etc. Got 5 gallons more didn't help. Removed inlet to regulator turned on key, LOTS of gas. Took reg apart again, aha, the check valve was stuck, cleaned with penetrating oil and lots of exercise on the set screw. Now works like a charm.