Make sure that the base is level - I used a 10 in by 10 inch wood log - (use a small level to make sure it is level) Place the Metal Drinker on the "level log or whatever" and remove the outer metal sleeve.. then fill the tank up with water. Now, the most important part that took me forever to figure out...Re-Install the metal outer sleeve and push it down until it stops/rests on the locking pin (do use the "locking slot") just let any part of the outer sleeve rim rest on the locking pin). When the tank is empty and ready to be refilled you can now use the locking slot to lock the outer sleeve so you can carry the entire empty Drinker to your faucet to be washed and re-filled....hope that helps....Charles

Very frustrated to see that this waterer is being described by the seller as "long lasting" and "durable," when after only a year or so, mine is all rusted. I've never added anything to my water like acv or anything. I thought mine was a fluke, but the reviews on this site confirm that this is a huge problem. Tractor Supply needs to stop offering this product or the manufacturer needs to make this right. My heating base is metal and states that it requires a metal waterer, so now I either have to replace everything or get another metal one and wait for it to rust in a year. Very frustrated.