Im Logged in but don’t remember admin password Version 10.6.8

So I am logged in to one of the two Admin Accounts. I DO NOT REMEMBER MY PASSWORD!!! I can see my password hint but it keps saying "The password is incorrect" when I try to enter the old password.

I went to system preferences > Accounts > Under the word My Accounts I clicked on my name and under my name it says Admin. How do I change my password without losing all my information? Do not have the disk that came with my computer.