Seriously dont need changing from factory mate
Go through the settings and hit factory/Reset.
You can lower the dwell if there has been LOADS of paint shot through it and everything has bedded in but I have never bothered. If you get any problems one of the first things to do is set it back to factory.
I honestly wouldnt change it but if you want to lower it start at 12 and drop it down.
Load of hassle for nothing in my opinion
Nige