A lot of people did a really great job with documenting what nostr:npub1y24gz5gwucl79vtv4ctwpysl0r5m4xyzu2rgulnr44ks3t5mt92q4nz2ad coded:

https://docs.btcpayserver.org/Payjoin/

https://www.youtube.com/watch?v=zGVCrwMKKn0

I'm thinking just to tie it all together with 10 minute step-by-step video, like I did for POS.