Step 1: open fuel door and remove the Easy Fuel trim ring from the fuel filler neck. it should pop on and off easily.
Step 2 (optional): cover filler opening with small cloth, paper towel, etc to keep from dropping any foreign objects into filler neck.
top view of housing and tab placement
bottom view of housing and tab placement
Step 3: remove the 3 8mm bolts surrounding filler neck.
proper spring connector placement with door closed
proper spring connector placement with door open
Step 4: reach up under fender and behind fuel door housing assembly and feel for 4 friction snap tabs. you'll need to pinch in the top and bottom tabs on the side opposite the hinge (back side of truck) and push to pop out the entire housing. it took me a few times of working all 4 to work it out of the lip of the fender to where it was free. you'll eventually slide it out in a hooking motion bringing the rear facing side out 1st.
photo shows hinge connector pressed down into place. before this photo it was about 1/2" taller and would not grab the hinge axle so no spring tension was on the door to keep it closed
Step 5: investigate the spring and the connectors. here's where i caught a break. i have read that some of these points break off, where as mine had worked itself out of index. the hinge axle connector felt like it was sleeved over the axle pin and was not indexed or pressed into proper alignment. i released the spring off the housing side felt the action of the door hinge to the connector and simply pressed the hinge connector back down into place. insert the spring into the hinge axle side first, then snap the spring into the housing side (spring will have full tension on it). test door open/close functionality to ensure everything is working properly before re-installing.
Step 6 (optional): while i had everything out i cleaned the rubber seals and wiped off some of the dust and grime buildup on both the housing and fender indention where the housing sits.
Step 7: re-insert entire assembly hinge side first and wiggle pinch tabs into position.
Step 8: re-bolt the 3 8mm bolts to the fuel filler neck.
Step 9: snap the Easy Fuel ring back to the fuel filler neck.
Step 10: remove the optional (Step 2) cover from the fuel filler opening.