Not hard but annoying. You'll spend a lot of time trying to squeeze between your steering wheel, pedals, center console and seat (you do have to switch the pedals). The other big problem is the upper tranny mount. If you look at the auto's frame mount it sticks up like this \. The manual one is flat (--). You will need a custom mount for the top of the manual tranny to bolt into. Place racing sells one but a friend of mine bought one a few years ago and it was garbage. They had to cut it apart and reweld it to make it work (this was a few years ago though, it might have been fixed). I've also heard you have to make sure the shifter cable remains in park or neutral or the car won't start (this interupt for that stays even with the old ECU removed). You'll also need a parts car to get everything out of, including the pedal assembly, master clyinder, slave cylinder, mounts and hard lines. Seeya.