unless your car is heavily modded already it would be better to sell the car and get another one thats already manual.

i did the manual conversion in my garage and it was a pain in the ass. the only reason i did it cuz my car is kitted and painted not to mention other shit that are easily transferable to another car (suspension, rims, i/h/e, nitrous kit,etc...), but i decided to swap to 5spd and maybe go f22 turbo somewhere down the line. auto tranny took a shit after 2 yrs of nitrous usage and my original plans were to h22 auto + nitrous. but having deck out automatic was getting old. dumping the clutch at 4k and spraying a 75 shot out of the pocket is way more fun anyways.

i also wouldnt advise it if your arent mechanically savy. if you are having a shop do it it will cost a grip.