Here was I would suggest:
1. If he still has the MIDI files to dump them all into his computer, grt some good virtual instruments and create the backing tracks
2. Go online and find all the lyrics to every songs that he has as a midi file.

3.


Computer: Macbook Pro, 16 inch 2021
DAWs: Pro Tools, Logic, and Maschine
plays drums, percussion, bass, steel pan, keyboard,
music producer/engineer