Do not try and remove a BCM fsb. Its a total pain in the @ss. They pin that &$^[$&$* on like its welded to the barrel. Shaving it will save you time and money and its very light and low profile. Or you can ask BCM to forgo the front sight and put a lo profile GB from the get go.
Assumption is the mother of all ****ups.
Know what you know, Know what you don't know. -Paul Pedzolt
"Jack of all trades, master of none, though oftentimes better than master of one" -Mynshul