Magpul ASAP sling adapter install?

[Dawson9a]

I got a Magpul ASAP sling adapter and sling for my birthday and tried to install it myself on my new Colt LE6920MP-B

The castle nut is stacked and I'm unable to get it off. I don't have a bench with a vise yet and have been unable to loosen it with the wrench I have. It has the three prongs but is still slipping off

Are there any gunsmiths in the area that can install this? I wouldn't think it would cost too much to do and I don't want to do any more damage than I've already done. (Nothing major.. Small scratches, etc.)

I've read up in this and tried all the suggestions.... No go.

Thanks guys!

Dave

 

[BradMacc82]

Where are you located?

 

[Dawson9a]

I'm in Eldersburg..

 

[Dawson9a]

Heading to South Carroll Sporting Goods this Saturday to get this installed..
Thanks!