CD Server – How to clean the hard drive?

I recently took over the technology duties for my organization. The previous staff person had been holding on to old hardware.

My plan is to donate the old hardware to a local charity, but first I’ve been cleaning the pc hard drives (using WipeDrive).

I recently discovered two cd server towers that I’d like to donate. My questions are:

1. I suspect each tower has a hard drive, am I right?

2. I’m having a hard time opening the cases. They are unlike any pc case I’ve opened. Does anyone have any tips?

Thanks!
Yesenia