How to upgrade a password storage scheme (change hashing-algorithm)

Question

I\'ve been asked to implement some changes/updates to an intranet-site; make it \'future proof\' as they call it.

We found that the passwords are hashed using the MD5

Answer 1

Add passwordChange datetime field to the database.

All password set before day X, check using MD5

All passwords set after day X, check using BCrypt or whatever.