How do I move a user's data, etc., to the Admin login?

Hi all.

Some time ago, when we bought this iMac, I set it up using what I was told were "best practices"; I created an Admin account, and a user account for day-to-day use.

Frankly, the setup *****. The User account is "flaky", exhibiting many random performance errors (for instance, I can't do a screen grab...) that don't occur over on the Admin side, or on any other of my computers.

What I want to do is transfer, copy, move, whatever, all the User stuff - data, settings, contacts, etc. - over to the Admin account, and then delete the User when I'm satisfied we've got everything.

Is there a way to do this easily...or am I stuck with re-installing the OS and (hopefully) migrating the data, etc., from the backup HD.