When you go to the yard first time (after your Premier registration is completed) you will need your ID, your buyer number, $25 in cash. At the yard they will check your information in their system using your ID and your buyer number (the name on the account and on the ID must be the same). After that they will take your picture, print out the buyer's badge for you (costs $25) and let you in.
Note: Next time you will just need to show your buyers badge to come in. An employee will escort you during your inspection.