. Place protective covering or bandages over the sore to decrease friction on the skin until the sore heals. Rub sandpaper disks or pumice stone over hard thickened regions. Soak feet or hands
.Then rub with a pumice stone and apply some moisturizer.
If still the calluses persist,then pls go in for removal by surgical means or with keratolytic agents (medicines that break up hardened areas of skin). Shaving or cutting off the hardened area on the skin by a doctor is also helpful.
Hope it helps.Take care and pls do keep us posted on how you are doing.