Icon grunges help-tutorial

Hi Problem with brushes- PS2
I place my icon on the background
then i did icon grunge brush on top of that *on a new layer* how do i change it so the black shows the pic and the clear area bw the black is white so i can write text on it...

EXAMPLE OF BRUSHES:
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MY ICON BEFORE BRUSH:
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after applying a certain brush:

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I am trying to get this effect: *sorry dont know who to give credit too*
http://s37.photobucket.com/albums/e68/LennonWoreChucks2/Tutorials/timpreview.jpg

or

definally this: http://img.photobucket.com/albums/v193/Kaliegh/Tutorials/Summer/Final.png