Directory Structure - My Dad has multiple user accounts, needs help

Question

My father (who is 87) has an iMac with OS 10.6.5 installed, apparently from a full install disk with upgrades.
The problem is, he has previous user accounts created under Leopard and Tiger, also in his name (with slight variations). The ~Applications folders in these old user accounts contain older versions of Safari, iPhoto, etc. etc. I think the Tiger user account was moved from an older Mac using migration assistant.
He auto-logs in under his 10.6.5 user identity, but has forgotten his user passwords for the two other accounts.
His dock icons point to various applications in the ~Applications folder on all 3 user accounts. So, for example, when he tries to access Disk Utility from the Dock, it says "this version of Disk Utility is incompatible with your system" (because it was created by Tiger).
He asked me for help with a seemingly simple printer issue, and the more I dug into his system, the worse it got.
How can I delete his two inactive user accounts without a) knowing the passwords and b) losing photos and documents proper to those accounts?

Answer 1

1. You need to be able to authenticate as an administrator (if his current account is an administrative account this will work). Just go to accounts, click the lock icon, and authenticate with his password. Then delete the accounts.
2. Before deleting the old accounts go to Finder and navigate to the home folders of the old users. Ctrl-Click on the folders, click on the lock icon, authenticate with an administrative account, and then add a sharing permission that allows his current account or all administrator accounts to read and write. You can then read and copy (and delete if need be) whatever files you need.