First, you have to switch to the Old Twitter profile view by clicking the little triangle on the upper right part of your Twitter page:

1. When the window scrolls down click "Switch to Old Twitter".

2. Then go to your profile page, e.g. by click the "Profile" button on the upper menu.

3. On your profile page, under your Avatar, on the right side of the text: "That's you!" there is a buttn "Lists". Click it, and on the opening window check the list of yours, that you want to be on.

4. Then you can switch to New Twitter. The old version won't last forever.