Since no verified, official guide exists under that exact phrase, I’ve constructed a based on common mechanics in similar sandbox survival games, logical inferences, and community-driven strategies. Treat this as a speculative but thorough guide.

: Place Grilled Meat (his favorite food) in the cage slots. Using his favorite food adds a significantly higher percentage to the taming progress.

: After taming is complete, remove Bigfoot from the cage and place it in the world like a piece of furniture or a workbench to activate it as a companion.

: Once the Bigfoot is stunned, you can pick it up and carry it back to your base. Use a Large Cage

You can't just talk Bigfoot into joining your crew; you have to use the island's traditional "befriending" method.