First you have to save your buddy list. To save your buddy list, you must login on your old screen name first, and then go to "My Aim" on the top left corner. Click on "Save my buddy list" and proceed to save it. Now log off your old screen name, and sign onto your new one. Go to "My Aim" again and click on load buddy list. Find and open your buddy list and press load. After all this, you will have your buddy list again on your new screen name!