Need someone to open mil spec upper ejection port for 450 BM

[Blasternank]

Can someone let me know who I can get to open up one of my ejection ports on my mil spec uppers so it can shuck those big brass? I know it's probably simple but I just don't want to screw it up so I'd appreciate it if a member here can do it or if someone can refer me to someone that can. I live in Fort Worth TX so if someone is around here that would be great as well.

Thanks.

[Texas Sheepdawg]

There is a gunsmith in McKnney, on University just east of 75. ( right down the street from CTD), I'll see if I can find his phone #.