The overall mods are not super difficult your other thread where you want a bank of these on a mounted platform is more involved. The hopper and extended mag is not complicated enough to need a write-up it is just going to take the longest the first time as you get the measurements down after the first one you can pre-cut all the pipe and slap them together. The bigger issue is you need to make a 3d printed hopper and the plan is not published for it yet. Your other option is to jank it out and cut up however many paintball hoppers to get it sized right. You might find something in automotive in the form of a funnel with a lid.
To do this mod from what i see the most difficult part is to rewire the blaster your going to gut the stock wire and put a connector up in the battery area or mod the battery area to use IMR batteries but since there is more to it we will go with a 3s lipo for about 12v stock motors should work fine after you clean up the wires.
First cut all the old wires out they wont be needed you will need a spool of 18 or 16 AWG i recommend stranded and in a soft silicon insulation rather than harder pvc they are about 6-10 Bucks for 6ft of black and red wire. The wiring will go as follows:
red from battery to switch rev switch likely the center post the other posts one is for open position being closed the other likely the used one is for push to close at least most of the nerf switches are like this. then red from other side of rev switch to the motors and fan black from battery to motors and fan
The blower on the top of the hopper is to push the balls through the system it needs to be able to push air out the barrel hopper needs a close to air tight cap to build positive pressure behind the balls. To do a full auto mod a part needs to be removed and a small bit needs to be cut this can be done with a pair of wire clippers or even a sharp hobby knife or the dremel.
shandsgator - without including the blaster, I would pay around $60-110 for that mod. The ammo part does concern me however, perhaps with a cheap enough Chinese knockoff you could do some ammo-wasting without much regret.
I need to find someone to do this mod and make 4-5 of them. I don't have the tools or the time!