"I need to get into my old email account but I can't remember the password. What should I do"
Sure, you could go through the steps to request a new password if it's offered, but maybe you can avoid all that with this simple tip.
Launch Keychain Access, search for the name of the account you want to discover the password for, double-click on it, and an information window will appear. Enable the Show password option and you'll be prompted for the user password for that account. Enter it and click Allow. The password will appear in the appropriate field.
You then pass along that password to the person you're helping. If you're not terribly trustworthy you might suggest that after you leave they take steps to change that password.
Christopher Breen