Easy with the right tools, as mentioned above. They also make free float rails for wich you don't have to remove the front sight/gas block. Another option would be to leave it and just cut it down. Either way, if you need help feel free to contact me.
Cataleya. This was Zoe Saldana's name in the movie "Colombiana"
https://www.youtube.com/watch?v=UHTOWFPGDKI
She is a SEXY woman and a bad B!^ch in the movie... would be an awesome name for a bad a$$ gun!!
I've seen lots of post for first builds and people commenting with tricks for putting parts together with dos and don'ts.
Anyways, a trick I have learned for getting those pesky retaining pins started, then finished with (in my opinion) the least amount of risk for damage is to use a center...