User blog comment:Jimeee/Dragonborn officially released on Xbox Live/@comment-5030041-20121205205737/@comment-4533502-20121207232213

Ok im going to make this really simple.

1. Complete Dragonborn.

2. Choose a perk.

3. The game will ask you if you asre sure.

4. Say yes.

5. You will lose a dragon soul and get back all of the perks from the skill that you have chosen.

6. You can do this at any time, to any skill, and as much as you want as long as you have dragon souls.

Sorry but you can't have a hight tier perk without the lower one.