Did you know that you can buy the exact same thing at Wal-Mart in orange color for like 3 bucks??? Other than this item being waaaaay overpriced, you do have some nice equipment that I plan on ordering in the next few weeks.
I can't unlock the caulking gun, to put the caulk in the gun
When holding the caulking gun, you need to press inwards, towards the gun, on the metal piece that the long plunger rod goes through. Below the rod, the piece comes down towards your hand. You press in with your thumb on this piece which releases the metal plunger rod allowing you to pull it out.