Thats exactly what you DONT want to do! the instructions on XDA for the skins says dont dl them from your phone and DEF dont install them if its a zip file. If it installed then there might be some problems... if u just extracted the files to your SD card then you should be able to delete the files once you find them.
Next time plug in your phone to your PC
set your phone to Disc drive and charge
download the file on ur pc browser
movie the file to your phones sd card (some place easy to remeber, you can create a skinsDL folder)
************make sure the file downloaded as an .apk**********
Use a file manager find the file on your sd card
click it, click app manager
install
done
*dont delete the Apk file image from your sd card you need it to uninstall the skin if you ever want to remove it.\
I have to head to work, google is your friend!