2 ways i know how after u unzip the file
1. after unzipping u get the abr file and put it in the adobe/cs3 folder in prestets then brushes- drop it there. or.
2. if u got all the abr in a diff folder which i did put over 200 of them - select all and open while u got photoshop is open. - i did this so i don't have to keep on goig to preset and opening diff file set.
this will take sometime depends how much brushes u got uploading in it.
gl.