Best way to remove callus on toe?

Depends. If t he thick, hard skin is on the bottom or top of the toe try a good lotion to smooth it or use a pumice stone th remove some of the skin layers.
Depends on the cause. Many things can cause calluses. Some reasons that one may develop a callus include: viral infections (warts), friction, pressure, repedetive trauma, and a limitation of joint motion. Some genetic conditions may also cause people to develop calluses on the hands and the feet. Treatment depends on the cause of the problem. Have it evaluated by a professional and get the appropriate treatment.