I agree with the others to implement it into his copywork, if he does that. There are places online that you can create a handwriting worksheet with your own words.
Besides that, though, I would just move on to other shorter passages, but continue to read James 2 to him several times a week (as done in the Scripture Memory System). Don’t necessarily have him try to recite it to you all the time. My kids seem to retain better when they are reciting along silently (in their own minds) while I read it aloud.
I’ve never been any good at creative crafts, games, songs, or hand motions, but if you are creative in that way, those things can help, too. Once we tried to set the parable of the mustard seed to a silly rap. The kids remember that passage so well. LOL. When it comes to games like that, though, I have a specific friend I have to consult because she is much more creative than I am.