Forget progressive overload. That idea belongs with Rip-plestiltskin and the other fairy tales.
If your bro like pushups, it shouldn't be hard to get him into chin ups, fat man chins(inverted rows) dips, different leg raises, walking lunges, lunge in place(split squats), sit ups on the decline bench, etc.
Get him going on a basic bw circuit. Use rep PRs or whatever. Start with something non-killer and frequent. As it gets easier, use more challenging moves. Teach him positioning, and the basic movements. After a short time, that stuff will get so easy he'll gravitate to the weights for the challenge.
You'll teach him, but he'll think it was all his idea.