I created a workflow which is a simple out of the box two person
approval. An item has been submitted into the workflow. The initial
approver is out of the office, and I'd like to mark it as approved.

I went into the workflow status page, clicked on the item, and clicked
approved - but the approval was rejected as the item wasn't assigned
to me.

I then logged in as the sharepoint admin, and tried approving the
item, but again, the approval was rejected.

Is thre a method by which an admin can either delegate approval of a
running item to another individual? At the very least, is there a way
for the admin to approve it directly?