its really not that difficult i have a post on it basically
1) have a friend down themselves on one side of the box
2) start the box spinning
3) when the weapon is bout half way up start to revive player
4) as you are reviving it will say press square to swap weapons or whatever, now let go of square and press it again quite quickly
then it should continue to revive the player but without the needle, instead you will have the traded weapon in your hand
congradulations you have now got 3 weapons +rep if helped