One of the features of Office 365 is the ability to add an authorized partner to help administer your environment. Luckily the steps are easy to make this Office 365 Partner relationship.
The partner actually initiates the process by sending an email asking to be the partner of record. The link takes you to a simple authorization page to allow you to authorize the partner as a delegated admin.
Removing partner relationships is as simple as logging into your Admin Center. Choosing Users -> Partner Relationships and selecting the relationship to remove.
Be sure to read the full agreement and verify the rights you are assigning to the partner. You can easily remove and edit these relationships.