Replacing engine computer

What is the level of difficulty in replacing an engine computer on a 1999 Jeep Grand Cherokee? And are there any special tools needed? :confused:

You need a scan tool also,has to be programed with a scan tool and it comes unprogramed.Chrysler's factory scan tool,the new Snap On scan tool and Vetronix scan tools will do this.Make sure you have the vin right,can only do this once and this is Chrysler's way doing this

What if I have the computer programmed by the dealership? How reliable are the remanufactured ones that you can get programmed?

The remans are good too.Do not ever hook up a set of jumper cables and jumper boxes backwards,OBD II Chrysler computers don't like this and will smoke it up.The Snap On Motus scan tool will program it which I forgot to mention.My local Snap On dealer said this.There is a core on the old one,about $100.00 for the core charge from Chrysler.