Like Timothy said. Now some things you might need to know.
When starting with an evil pet and going to the good side the pet will start off being grey. This makes the pet attackable by other good karma creatures, and also other players. You will need to kill 4 bad karma creatures to gain enough to turn the pet Blue. Then just work him up past level 10 to 15. I would get used to using the Aggressive and defensive settings to help control him at the lower levels.
Also I would try to stay away from using the litlle wierd looking creature, I forgot its name but starts with a P. One of its abilities is that it will heal itself and the controling character. A bug was mentioned in another thread that says it will actually heal the Boss. I dont know if this is confirmed or not, and I dont want to waste time in training to find out that the Boss will not die.
Good luck