if your ok with tools, it isnt going to be bad if they assembled it correctly. they should of used copper anti seize. you just wont know till you start into it. if your going to put in a custom barrel nut or the original delta spring. you could need some heat on the receiver , from a heat gun. maybe a vise grip and a dead blow , to tap it out, while locked into a vise.
strip your bolt firing pin and ejector and use a live or dummy round to headspace . i think thats how we did it. but your going to need a set of blocks, some pin punches/ a solid vise/ torq wrench and some patience .
