You can add or remove profiles from a list in two different ways.
1. Click in Audience > List. Select the list you wish to iterate and add/remove profiles directly from that list.
2. You can add or remove a profile to a list by searching for that profile in Audience > Search. Click on the profile and select the list you wish to add or remove from the dropdown menu. All lists highlighted in blue are lists that profile is associated with that profile.