To transfer the ownership to a colleague, head for the top right corner where you see your name, and click to open the menu.
From here, click My Profile. Here you can update the account name and email to match the new account owner.
Next, the new owner can set a new password. They will need to head to the login page and request a password reset from there with the new account email address.
This way, you are able to easily move the account ownership in a secure way.