Getting your lumber into the kiln is simply a matter of restacking with stickers. Unless of course you have a forklift or equivalent to lift your entire stack at one time and set it down in the kiln. The two large doors at the back of the kiln make kiln carts impractical, but it makes hand loading or forklift loading much easier than end wall doors.
To ensure a reasonably flat and stable surface to stack upon, I put down five treated 2x6s on the floor. This was mostly necessary because I had some buckling of the floor plywood and I felt the 2x6s would minimize any impact on the lumber because of the slightly uneven floor. The baffle is rolled up to the bottom of the fan deck and a few spring clamps hold it temporarily out of the way.
This kiln allows a four foot wide lumber stack. I place the stack so that there is about the same amount of space in the front of the stack as there is in the back of the stack. Boards are loaded and stickered until the stack reaches the top of the front (south) wall. Sixteen layers of 8 foot boards brings the capacity to about 512 bd-ft maximum, although the stack is probably closer to 500 bd-ft. This first stack in the kiln went 15 layers for a capacity around 475 bd-ft.
Once the last layer of boards are loaded, a final row of stickers is added and the corrugated collector panels are placed on top. You may want to add weight to the stack to minimize bowing, but I didn't for this first test run.
With the collector panels in place, the baffle is rolled down and tucked under the edge of the rear panel. From the south side of the kiln the sun only sees a totally black collector area.