Don't know the exact proceedure, but all you do is take the battery leads off and leave off for around an hour (some people say 5mins,30mins etc, but I do it for 1 hour to be sure). Once you have reconnected the battery, if you want the best performance, drive the car around like you stole it for about 100km, or if you want the best fuel economy, drive easily for the first 100km.
To get a firmer shift, there are two methods I know of. Firstly reprogram the EEC, with a trans chip etc, or modify the valve body to increase the line pressures in the trans. The modified valve body does cost more, but I think it is the better way to go.