1.Extract the .rar to a folder.
2.Choose which skin you want.
3.Copy and paste the folder in to your (Disk):\Steam\Steamapps\Sourcemods\zombie_master folder
Delete the v_mac_zm and v_smg folders in the materials\models\weapons folder
Notes: You can see all the skins in the .jpegs provided in that folder.
Screenshots that were posted on FPSBanana are of the "No Logo" Skin.
Original version released is included for those who like them.
(It got a horrible rating, So I don't see who would use them, other than those who did not comment.)
Lambda Logo (from HL2)
Umbrella Corp Logo (sorta goes with the theme, I personally didn't like the idea but I knew other people would.)