So I got my NOS gasket from Green Sales (Right On!) and proceeded to try to solve this recurring nightmare I see posted from time to time.
Tools:
Long azz extension
Universal
Spark plug socket that still has the rubber insert in tact
7/8 Deep well socket (no insert)
Ratchet
All of the above were in 3/8 drive, YMMV.
1. Insert the filter cone into the spark plug socket. Push it in there until the hex bottom of the filter is against the bottom edge of the socket.
2. Insert grommet.
3. Drop plastic washer in the reservoir.
4. Insert pump through grommet. This part is important: The finger that lines up in the grove in the bottom of the reservoir must be in that groove for enough threads to be exposed to start the filter screwing on operation.
5. Look like you are having a seizure until the washer is on the threaded part of the pump sticking into the reservoir.
6. Insert Universal into spark plug socket and then insert the extension.
7. The threads angle back to the reservoir wall that rides on the inner fender. Apply a little pressure and turn the extension. There should be an obvious bend in the universal when you are lined up correctly. Just get the threads started. It's easy to accidentally have the pump shift here. A second set of hands is helpful to hold the reservoir/pump in position.
8. Remove tool and replace spark plug socket with 7/8 deep well. this will fit completely over the filter. Hand tighten the filter.
9. Attach ratchet and give it a final seat. No need to get crazy. It's plastic and rubber. Just so it feels like it's fighting back. For me it was 1/8 turn or so.
10. Revel in your victory.