I have a TC25D with the mid mount mower (this is the same tractor as yours with a lower horsepower engine) and like the others have said I have to lift the front end with the bucket and slide the mower in from the side. The problem is that my mower has two wheels on the rear that only roll forward and back. They do not pivot, so when I would try to slide the mower in from the side these wheels would have to skid across the floor. To solve this problem I found two of the small three wheel furniture dollies, the one's that have a small cup in the center and I set the rear wheels on the mower in these and now the mower is a breeze to slide under the tractor.
Hope this helps.