I'm not so sure I'd put it in his stall, depending on how afraid of it he is. If he's extremely afraid of it, put it on the outside, right in front of his stall door, if he's able to view it from there. Also, yes, as charlicata said, walk him by it constantly. When he's comfortable being around it and sniffing it comfortably, start kicking it and stepping on it so that he knows what noise it makes when he touches it or steps on it. Be patient, and good luck to you!