If you're an Account Admin, you can change the owner of a contact. This can be done to multiple contacts at once, or to a single contact.
Changing the owner of a single contact:
1. Open the contact card of the contact you want to reassign and click Edit.
2. In edit mode, select the new owner of the contact and click Save.
Assigning multiple contacts to a new owner:
On the contact page, click the check box next to the contacts you wish to reassign. The checkbox appears when you hover your mouse over a contact. Then at the top of the page, select Reassign Owner.
2. Select the new owner, and then hit Reassign!