HFCM Servicing, at least the way I do it, and I have been doing it this way for the last 5 years I've had my truck.
Park the drivers side up on a set of ramps, to get the truck tipped toward the passenger side
Slide under a drain pan, and yourself from the passenger side of the truck..... this helps to keep you away from the fuel mess.
Remove the 6mm allen head plug from the lower right side of the HFCM. You will need to us an "L" shaped allen wrench to fit between the transfer case and the HFCM if it is a 4X4
Allow fuel to begin to drain from the HFCM, go under the hood, and loosen the secondary fuel filter lid. This allows the fuel to drain from the secondary filter housing, and the line to it,
When the fuel finishes draining, replace the 6mm head plug into the HFCM (So you don't forget to put the plug back in)
Take the 36mm socket and begin to remove the large cap from the back of the HFCM. This cap is the same size as the oil filter cap under the hood. Experience with my truck is there is only about 1 click's worth of movement of the ratchet in the area where you can place the ratchet and socket into the frame rail, just in front of the transmission cross member.
Once you have the lid out far enough the O-Ring clears, you can spin it out by hand. You will have to work the lid and filter out separately, they will not come out together.
Remove and replace and lubricate the O-Ring on the HFCM lid, work the new filter back into the HFCM and the lid. Pop the filter into the lid and thread the lid back in. Tighten the lid back into the HFCM.
Finish removing the secondary filter from the housing under the hood. Remove and replace and lubricate the O-Ring, and replace the new filter into the lid and tighten the lid back into the secondary housing.
Once everything is back together, cycle the key from off to run 3 or 4 times, this will refill both filters and the line. Start the truck and check for leaks,