Take the roll bar before your buddy changes his mind. You can figure out how to tap it later. You could use an item called a plusnut. WeatherGuard ladder racks come with these from the factory and they can be bought at any weatherguard dealer. They work like a molly bolt but are designed for automotive use.
Tom
1985 CJ7
4WheelDriveWeb
Tom
1985 CJ7
4WheelDriveWeb