Lol... He makes it look so easy. I was just putting on the upper BC tactical handguard (I like the look of the wood). My lower handguard was slightly higher on the left, and both had little burrs of beaver barf preventing the rear of the upper handguard from seating. A half hour of filing ensued. Then I realized that despite being seated, the holes for the pin didn't line up. Examination resulted in finding the problem: the upper handguard was slightly too long (pressure fit, very tight tolerances). After another 45 minutes of filing the handguard, I could use an allen key to pull the holes into alignment from the opposite side of the pin, allowing the pin to be inserted. Its VERY tight.