AP is great....the major things to remember is measure 4 or 5 times, cut a little less than that and then try the pieces on. Also have fun with it!
Some of the tools I used was sharp knife (always keep it sharp) , ruler, clamps, a lot of tape, a metal straight edge to help cutting. I'd also say have a measuring tape on hand to help. Get some rare earth magnets to help hold the shims on while they dry. I'd recommend using E6000 glue. Its strong but still allows you to take parts apart in case you have to make an adjustment. I had to use ca glue to get the sniper plate to stay on. That stuff dries quickly and can run where you don't want it to so be careful if you've never used ca glue before. Also, snaps, the heavy duty kind and elastic straps that you can get at any fabric or hobby store.
Along with replacing the mic tips and getting s-trim, I'd recommend getting a darker lens for your helmet. Helps keep light out and people seeing through. Also, and just a suggestion, paint the inside of your helmet black. It'll help with sun light and kids will see more darkness when they try to look up into your helmet, makes it more mysterious
I got the rivets, lenses, s-trim and magnets from trooperbay.com
Hope you'll make a build thread where everyone can help you out and of course be nosey We do love helping and pics!
Best of luck and we're always here to help fellow troopers!