Making Gradients

I've checked the memories and I can't find this anywhere, so I'm posting =) Bear with me if I might have somehow missed it.

I downloaded magdalenaicons gradient image packs, and I was wondering how I go about turning them into proper gradients for PSP8? I know you can make custom brushes and import those etc, but I haven't ever fiddled with gradients so I have no idea - please help if you can?