Replace power cord with 12 gauge wire
A source for 12 gauge wire is an extension cord with the female end cut off, or one can buy quality rubber jacketed wire material and attach a male plug which is probably better quality. Either way will be fine though as it provides a 12gauge power supply instead of the wimpy 15 amp computer cord the compressor came with.
Remove the top curved shield on the power cord side of the compressor to improve access. Remove the factory wire from the backside of the computer power cord socket and from the switch under the top shield. Remove the side shield with the power cord socket. This shield will be abandoned. Bolt new strain relief to the two left side shield brackets. It is recommended that you remove some paint from the bottom of the frame were the head of the motor mount bolt you will be attaching the ground wire to contacts to complete the ground to the frame. Strip enough outer jacket from the new power cord to get the ground wire down to the motor mount bolt. Trim the line and neutral wires to fit to the power switch nicely and crimp on spade connectors. Run the new power cord through the strain relief and attach the line and neutral wires of it to the power switch where the original wires attached. Run the ground wire from the new cord to a motor mount bolt. Strip an inch or more of insulation so the copper wire will wrap around in a U shape around the bolt and the insulation will not be pinched under the washer. Wrap wire around bolt in the direction of tightening the nut and tighten the nut. Check all the motor mount bolts for proper torque; mine were all quite loose.
Mount water pump
The strain relief plate is large enough to use to mount a water pump to. Trace the mount holes onto the aluminum and drill for mountings screws.
New head installation
I don't know if it matters but I smeared my gasket with a very thin rubbed on coat of SuperLube or 100% pure silicone grease. Use the new longer head bolts. Use the included anti-seize on all the bolts. Coat the entire bolt to prevent corrosion. Tighten head bolts in a cross torque pattern (opposite sides) back and forth a bit at a time. Tighten enough to compress gasket. You may have to slightly bend one of the side panel mount tabs out of the way to clear the filter. Install filter. The filter has a foam element which has better silencing properties than a paper element. One could choose to upgrade the filter/silencer to a better quality one like the industry standard Solberg, but the included filter will work just fine.
Compressor oil/drain plug installation
It is highly recommended that you upgrade to Chemlube 501 compressor oil which has a 500 degree f. flash point will not combust and gum up the high pressure piston like petroleum oil will. If changing to Chemlube 501, drain oil through oil plug, then remove rear crankcase cover and remove all oil with paper towels and finally a brake cleaner spray can wash. Let dry. Clean the rubber gasket. Pour some Chemlube over the connecting rod ends at the crankshaft, replace crankcase cover, and if your drain plug/sight gauge survived removal re-use it if you wish, or use the one included in the kit. The original in my compressor disintegrated as soon as I put the slightest torque to it. If the original one disintegrates, remove it with a large screw extractor stuck in the remnants. If using the PVC plug included in the kit, wrap the threads with Teflon pipe thread tape (remember to wrap in the same direction as screwing in the plug so that screwing in the plug does not remove the tape) remove witness hole screw, fill crankcase with oil until it comes out the witness hole, wrap screw with Teflon tape, and replace screw. Note: do not over tighten drain plug. Pipe threads are tapered and over tightening could break the crankcase cover. It shouldn't need to be any tighter than hand tight with just a tiny bit more with a wrench to make sure it stays put. If it doesn't leak, it's tight enough.
It is also recommended if replacing the petroleum oil with Chemlube that the high pressure cylinder be opened up and the piston and rings cleaned with brake cleaner to remove the burned oil gunk that is already there from the few minutes the machine was ran at the importer. Do not remove the rings, just use paper towel and carb cleaner to spray them clean. Remove and clean the poppet valve and spring in the head. Smear spring with SuperLube or 100% pure Silicone grease and then remove it all with paper towel fit in between the spring so it's corrosion proofed but not goopy with grease. Mine was already super rusty from the few minutes it was ran at the importer so it is highly recommend this spring be cleaned and lubed for long life. Make sure piston ring gaps do not line up. Replace head on piston with a slight circular motion to get the rings to fit into the cylinder.
Note: I'm sure anyone with experience with PCP guns will know, but if buying 'plumbers grease' as a source for 100% pure silicone grease, if it smells like an oil refinery, that's not the right stuff. I highly recommend SuperLube as a modern replacement for silicone grease. It is highly regarded in the Scuba industry and has superior characteristics over silicone.