Can I get a little advice? I have an E-Maxx 12020 with a strobe slipper on 14 cells. The Warrior 8XL that was on it died and I have a Fiego 7XL. The 5 mm shaft does not have an indention in it. Do you dremel one in? Anything to be aware of when doing it? And there are no gold plugs, do you directly solder to the ESC? Thanks!
You can solder directly to the ESC if you want or just buy some bullet connectors. And you can Dremel a flat spot on the shaft. Just watch out for metal shavings going into the motor. You can use a small ziplock bag, put the motor in and poke the shaft through the bag, this should protect the motor. At least that's what I do, and works for me.
You can direct solder or use bullet connectors as bluonyx said. As for dremeling the shaft, I just put tape over the holes, and that seems to work fine.
Just thought I'd point out that you should NOT cut the motor wires. Only the last 1/4" or so is solderable. Not sure if you were thinking about doing this, but better safe than sorry...