The best advice I received from other TrailManor owners is to level the unit before attempting to open it. I use a device that lifts one of the tires for side to side leveling. Front to back is easy using the tongue jack. If you open in then it is not level, it will tear itself apart and reduce the life of the trailer.
The 2nd bit of advice is to get an Andersen weight distribution hitch. This is particularly important if you have a smaller, front wheel drive vehicle. If you are using a Chevy Suburban, you probably don't need it.