Sounds like your well on your way, I'll just toss up some pics for ya before you dive into the project.
While your getting that 36mm socket for the fuel filter grab a set of fual/ac line quick disconnects, something like this,
Once you get the filter out and drained undo the 2 lines on the left of the pump (I believe they have some clips, just pull them up and the lines come off) then undo the other 2 lines on the right side (here is where you need to disconnect tools) then undo the 2 wiring harness connectors and finally remove the pump from the frame rail by removing the 4 bolts on the outside of the frame (12mm I think?) Make sure you got a bucket of some sort for collecting the fuel from the filter and lines and more that will come out when you can tip the pump to pull it out.
Here are some pics from when I pulled mine apart for the same reason your describing.
All apart, notice the red gunk at the bottom, this is where the WIF sensor resides and what seemed to keep mine on.
Other side, showing the cover and more gunk around the drain plug. With mine the drain plug was seized to the cover. WIF sensor is the black on on the left.
One more thing you might want to check out sometime is the updated drain plug. It sounds like yours is still easy to remove but they are known to seize to the aluminum housing, and then stip out when you try and remove them. Ended up having to drill mine out.
Here is the updated plug that is beefier, can put vise grips on it if the 6mm allen plug strips, and it helps in wicking the fuel/water out of the housing so as to not make soo much of a mess.
I believe these are the appropriate Ford/International Part numbers:
Diesel Technician Society
If those numbers don't work, ask to see if they can get the HFCM drain plug from an LCF truck.
Or some aftermarket vendors also carry the plug,
Diesel Part # SB6E7Z9C082A - HFCM Water Separator Drain Plug Upgrade - Diesel Performance Parts
Best of luck and hope you can get back to running good without too much time or money.