Step 1: Give injured leg two days of rest.
Step 2: Continue to walk 15 miles a day on injured leg, ignoring pain that is actually quite severe.
Step 3: Shun doctors.
Step 4: Shun the pain. Walk through it.
Step 5: Occasionally push it too far and re-injure it a little bit.
Step 6: Repeat steps 2 through 5.
Step 7: It gets better (mostly?) eventually, so be proud of your completely irresponsible healing technique.