To change the bundle administrator, display the membership details for the member you want to be the new bundle administrator, then click Make administrator.

The former bundle administrator now becomes a regular bundle member.
The Make administrator button is grayed out if the current bundle administrator has recurring payments set up. To change bundle administrators in this case, stop the recurring payments for the current administrator, then switch administrators. Now, renew the bundle membership by clicking the Renew button on the Membership tab for the new bundle administrator, then click Generate invoice.
For more information on membership bundles, click here.