To request that an already existing 6-8 athlete appear within your User Account, first click on "Athlete Profiles". Then click on the + sign in the bottom right corner. Choose "Existing" and enter that athlete's 6-8 ID number and email. Then press "Request Access". 

The 6-8 ID number is the number that appears within an Athlete's Profile. You must get this number from them in order to request access to their account.