To edit or delete lists
Go to your profile page.
Click on the Lists tab.
You will see lists you’ve created and other people’s lists you follow under Subscribed to.
Click on the list you’d like to edit or delete from the lists you’ve created. Click Edit to update your list details or click Delete to remove the list entirely.
You cannot add or remove people from your list on this page —you must do that from the profile pages of each individual you wish to add or remove.
To subscribe to/follow other people’s lists
Click on Lists when viewing someone’s profile.
Select which list you’d like to subscribe to.
From the list page, click Subscribe to follow the list. You can follow lists without following the individual accounts in that list.

via Using Twitter lists | Twitter Help Center