Attach the F-1099B Lower Wing Root Fairing to the T-100SB Shim, T-1001-L Fuel Tank Skin, F-1076 Center Bottom Skin, and to the W-1004-L Bottom Inbd. Wing Skin. Match-Drill #40 and cleco the tank skin at the five locations using the 3/32 holes in the lower wing root fairing as guides.
When I originally did this, I trimmed too much off the left fairing, so I ordered a new part. The new one fits much better.