For a quick infusion, you can use fresh LEAVEs. For a solar infusion, let them dry first. Don't use the roots!
Cover the LEAVES completely in carrier oil-- OLIVE, COCONUT, SWEET ALMOND, or JOJOBA ARE ideal
heat on low IN A BAIN MARIE FOR 2-4 HOURS. ONCE COOLED, STRAIN THROUGH A CHEESECLOTH.
keep it SOMEWHERE DARK AND DRY, and enjoy!
for the full recipe & how to use COMFREY oil