I actually tried this a while back. My thinking of going to 2WD would be a little faster, but easier to drift and be a little more interesting to drive. The conversion was basically to take the front dog bones and drive cups out, and then tape up the holes to stop dust getting into the front diff.
If you've got a TT01, you'll find that the centre driveshaft also powers the rear diff, which means you need to leave it in (and you can't cut it as the length of the shaft keeps the pinion to the rear diff in place as well).
My setup was a stock TT01 with the silver can motor, ball bearings all round and I think a 27T pinion and 52T spur from a F201 type kit. So nothing too wild.
The results weren't what I was expecting. Maybe I'm just can't drive and no good with the throttle. But what I found was that any bit of braking (you only have rear brakes in 2WD) or anything more than half throttle with any steering lock and the thing would swap ends.
I ended up going back to 4WD after a few packs because it was just so hard to drive. I think for interest the ball bearings and gear change was much better value and fun (especially with the slippery stock kit tires) than the uncontrollable 2WD.