I have a troy industries claymore brake. I did the build while living in NJ. Now in PA. The only difference I've noticed in a brake and flash hider is an extra cut out on the bottom. Can I turn my brake into a hider by adding another cut? It's pinned to a 14.5 inch barrel. If so, what could I use to cut it? I'm not extremely mechanically inclined, so this information  doesn't  come naturally to me. Thanks in advance.

No, you can't usually turn a brake into a flash suppressor. A brake has a small opening in the front for a bullet to exit. A suppressor has a conical opening. Here's a picture of some brakes and one suppressor. The one on the far right is the suppressor. -W

No, you are better off picking up an extended A2 flash hider and having it installed by a proper gunsmith.  

I use this one, it's a bit more money but goes well with a pencil barrel.

http://www.adamsarms.net/vdi-manimal-extended-flash-hider

Or this:

http://www.midwayusa.com/product/484423/schuster-extended-a2-flash-hider-1-2-28-thread-ar-15-matte

nothing wrong with comps, i prefer them to flash hiders

Some good comparison videos of MB's/FH's:

https://youtu.be/3FD-Rou9-9A

https://youtu.be/ehH4SZDb3SE

Do some research, pick the one that's right for you, and have a GS replace your existing one.

I wouldn't waste time/effort/money trying to mod the claymore.