While tagged, the Runner can spend and 2 as an action during the Action Phase to remove one of his/her tags. The Runner pays the cost, and then returns the tag to the token bank.
While tagged, the Runner may, as an action, spend and 2 to remove the tag, returning it to the token bank. The Runner can repeat this action as many times he likes, provided he has the clicks and credits to pay its cost, and as long as he has a tag to remove.