Remove Other Users' Apple ID from Computer

Hello,

I am using my work computer, and before I had it, another employee was using it (who is no longer with the company).

I keep being prompted to udpate apps, but when I click update, it asks me to sign in to her account.

They aren't new apps, but general ones that come with the system like iMovie and iPhoto.

How can I remove her information so I don't keep getting prompted to update these apps (and not able to update them)?