How to reset master HD password in T23

[aleks3]

I bought a used thinkpad t23 off craigslist some time ago. The seller set a user HD password in bios to "alex" (my name). Now I want to remove it or at least change it, as I want to give it as a gift to someone else. However, it seems to that to change the user HD password you have to have master HD password, which I don't, and the seller isn't responding to my emails.

This isn't the master bios password, which seems completely separate.

Any help is greatly appreciated.