That's a rather vague request. Do you know what engine you want to put in it? What drivetrane is in currently in the Jeep? You have to be careful, a V8 will undoubtedly put out more torque, so you have to make sure your drivetrane can handle the output. Installing the engine is fairly easy if you have another CJ to pull from. You'll have to change the motor mounts, but everything else should bolt up. If you can be a little more specific, so can I.
It's not so much a labor of love as it is shear determination.