...
Make sure you are logged in to your own admin UI, click on ‘partner’ in the main navigation menu and proceed to click on ‘manage partner’. Find the relevant partner with the partner filter, following the instructions in this article.
Logging in directly
When you have found the relevant partner, a row will be displayed containing the partner’s UID, his main ad space and his full name, along with several icons related to partner functions. To login to the account of the partner, click on the on the right. If you do so, you will immediately be taken to the partner’s account and logged in.
...