So no airbag, yes?
Depending on the type of custom wheel all that should be required is to pop the horn button off and you'll be staring at a big 'ol nut. Somewhere in the range of 3/4" - 7/8". If you're just tightening it all you need to do is snug it down. Some blue locktite wouldn't hurt.
If you want to take the wheel off you may still need a steering wheel puller to do it. Something like $15 for one at an auto parts store or Harbor Freight.
No one specifically makes an aftermarket steering wheel adapter that I've seen for TJs because of the airbag system. Most people that have a custom wheel on a TJ buy a YJ adapter kit and modify it to work. So tightening the steering wheel nut may or may not get 'er done.