You must have one of the following roles in order to see the Collection Evaluation buttons.
Individual subscriptions to Collection Evaluation:
Group subscription to Collection Evaluation (rare):
If you see these roles in the list, select the one that is appropriate for your library and hit Save to give yourself access.
If you do not see those roles in the list, they have not been assigned to your account. If you haven't requested it, you can get a quote for access by filling in the WorldShare® Collection Evaluation Quote Request. If you have requested it, email orders@oclc.org with your name, library name, OCLC library symbol and the invoice on which you paid for it and they will make sure your settings are correct.