You can easily run hexes on the back of your 201. Simply install the standard width hexes from a 22 on the axles. They fit right over the stock pins with a slight push.

This however makes the car 1mm wider when using Kyo/TLR wheels. The simple solution to put it back to stock width is to remove the N13 spacers from in between the outer bearing and wheel washer (#9804350) on the front side of the axle and install them on the inside of the wheel hub by placing them on the axle before re-installation. Thw 9804350 washer is tapered to meet the inner bearing race so be mindful of the direction you re-install it.

To get 12mm hexes on the front you will need all of the appropriate AE parts to do so. (Knuckles, axles, bearings, hexes)

Take a 3mm drill bit and drill out the king pin holes on your 201's knuckle carriers. (Do not drill out the AE knuckles)

Install a 3x25mm bolt of your chosing (Button, Cap etc) and screw through the AE knuckle until snug then back off 1/2 turn or until knuckle is free in carrier. I used bolts that were completely threaded.

For the tie rod ball ends I used a bolt up through the knuckle and used the 53869 ball nuts.