Stick a pin/ sewing needle in some fire then pop your blister with it by putting the hot needle under the blister. But don't get the needle stuck in your foot... I've done that.
...Or you know, just leave them be and wear soft shoes for a while. Better than attempting to steralise a pin using fire or wrapping your foot up in bandages which will reduce the air to it, imo.
Everyone in this thread is bullshitting you. The only real solution is to cut off the limb/appendage that has blisters. Hacksaws usually do the trick. Best of luck.
Go for a long walk, up and down rocky hills in Derbyshire, like I did today. Obviously the best thing to do with blisters, so much for weaing sandles.