OK... I can help you, since I had the same series tractor, but mine was a BX22. The loader valve stays on the loader when the loader is removed from the tractor. You have to pull the cylinder pin along with the top pin to remove the valve and post assembly, and put it back onto the tractor, using the large pin that goes at the bottom of the frame to retain the loader valve post. Now, you have the cylinder on the loader hanging down, and what I did was to buy another post, and use that to keep the loader cylinder in place, and also to keep the pins from becoming lost over the winter.
Now, here comes the bad news. That loader was sold with 2 different valves, and if you don't have the correct valve, it will not work with the hydraulics of the snow blower mount. From memory, they were referred to as a 3 way valve, and a 4 way valve, and the one that you need is the 4 way valve. While I don't care for redirecting people to other forums, this time there is no other way. When you read this post on TBN, you will understand more about these valves. Pay particular attention to post #12, because that will help you to figure out exactly what valve is on your tractor. Don't hesitate to PM me if you have additional questions. I know your tractor extremely well, having owned mine for 18 years.
https://www.tractorbynet.com/forums/threads/bx22-4-way-valve-or-3-way.26389/