I received a bottle of olive oil as a gift, and discovered later the oil came from a farm that used heter mechira. Since I don’t hold by the heter mechira, can I give the oil to someone else, or how can I dispose of the oil?
Since most poskim agree that it is considered to have kedushas shmitta, and from the date of your question it is surely after the time of biur, which was around Shavuos of last year. Food that was kept in ones possession after the time of biur may not be eaten by anyone. You can either burn it or bury it, whatever is easier for you.
Ramabn Vayikra 25-7, Rash Oholois 18-9, Chazon Ish 26-1.