Not sure there is much of a guide other than the bit in kobopatch.yaml:
Code:
## TRANSLATIONS ##
# Optional, use only if lrelease is not in PATH and if translations are needed
# lrelease: /path/to/lrelease
# Uncomment the following to add translations (replace lc with the language code)
# translations:
# src/whatever.ts: usr/local/Kobo/translations/trans_lc.qm