Transparency help

I made a batch of icons using a ripped photograph brush. The part of the brush that is not a photograph is just plain white.

I use PSP7. Short of sitting there and erasing the white parts, is there any easier way I can get rid of them and make the edges of the icon transparent? I've tried using the magic wand tool a bit, and it made the edges too harsh. (I'm not too skilled with the magic wand tool - so if that's what I should be using and am just using it wrong, correct me.)

Here's the icon, just for a visual reference:
<-- see the white areas?

Any help is really appreciated.