It's really easy but requires a few tools. You'll need a gas cylinder lock wrench (Fulton), Castle nut pliers (Brownells), a 3/8" wrench or combo tool and a 1/16" allen wrench. Remove the set screw in the flash suppressor/muzzle brake, then unscrew the castle nut to remove the FS/MB. After this remove the gas plug and gas cylinder lock, tap the gas cylinder off using a wood block or rubber mallet. Now install the shims that you think will lock things up (usually only requires two of the three shims). Install the shims, then the front band then the gas cylinder (tapping back on if needed), tighten the gas lock by hand, it should stop at approx. the 4 or 5 o'clock position. Use the wrench to tighten it down to the 6 o'clock position at which point the front band should also be tight. You may even want to get it to stop at the 3 o'clock position because your first few shots are going to break in the shims which will cause things to loosen a little. Install the FH/MB and it should be ready to go. Hope this helps.
I was also opposed to the screw method until I got one back from HueyGunner on The M14 Forum, he does excellent work at a reasonable price. I have yet to have any problems with it in over 1500 rounds. I don't even miss not being able to shut off the gas system either, one less thing to think about for me.