rimfire rifle muzzle device removal help!

[gotaglockinmyrarri]

i have a m&p 15-22 and I'm not sure about the law with taking off the muzzle device? does anyone know if its pinned or welded? i bought a new rail for it and i need to take the flash hider off it. if its pinned or welded ima have to take it to the smith but they'll charge me for removal,a new one,and installing it. plus id have to pay for them to take my stock barrel nut off and put the new one on. id much rather do it by myself.