Instructions
Load "Team Fortress 2" to the main menu and click "Items" under "Customize."
Click the "Crafting" icon, which is the second option on the list.
Click "Smelt Class Weapons," and then pick two Sniper weapons you have in your backpack. Smelting these items will produce scrap metal.
Click "Fabricate Class Token," followed by three additional Sniper weapons in your backpack. These three weapons turn into a Sniper class token.
Click "Fabricate Slot Token," followed by either three primary weapons, three secondary weapons or three melee weapons. This produces a slot token.
Click your backpack and select the three items you just crafted. This will randomly produce either a Razorback, Darwin's Danger Shield or Jarate.