Ok so I got the kit and installed it yesterday. The only decent photo is shown above. (after this I was too grubby to handle the camera) Front of the trailer is to the right of the photo. I don't know which way the shims are supposed to go. They appear to be symmetrical fore and aft and left to right. I decide to install mine with the open channel of the shim facing out but I'm sure they could go the other way.
The procedure is as follows:
Jack up and block the trailer high enough to get the wheels off.
Block the axle so that it won't fall when you remove the bolts holding it on.
Cut the zip ties holding the brake wiring to the axle so that when you drop the axle down you don't damage the wiring.
Remove the bolts from both sides.
Lower the axle to the previously positioned blocks.
The photo shows the starboard side lift shim in position but before it's bolted up.
Bolt the shim to the axle then lift the axle and bolt the shim to the frame. The axle can be lifted by hand but a jack might be better. (Note: after I lifted the axle in place and inserted the bolts and nuts hand tight, I jacked the axle up before tightening the bolts)
Snug up the bolts but don't tighten them.
This is hard to see in the picture but the axle bracket that's welded to the frame has a notch in it. I lined up the center post of the shim with the notch.
Then I aligned the axle with the frame.
I measured from the hub to the front corner of the trailer frame.
Then because the nuts were still not tight, I was able to use a rubber hammer to persuade the axle to move.
I moved the axle until the hub to frame measurements were the same on both sides of the trailer.
Then I snugged up the nuts.
It helped that I had an 18v impact driver. The nuts and bolts require a 15/16ths wrench.
New zip ties on the brake wires and remounting the wheels finishes the job.
It took me all morning to do this job maybe 4 hours but that includes moving the trailer to the driveway, making wood blocks from scrap 2x12 and jacking everything with a small bottle screw jack (painfully slow)
The threshold of the door now measures about 14 inches above the ground so I think a retractable step is in order. A small plastic 7 inch high step stool we use around the house works fine.
After this I reinstalled my WDH (E2 Trunnion 600lb bars). I used the stock tow bar (about 1 1/2" drop) and was pleased to find that with 5 washers and the L brackets in the middle that my front fender well measurement was right on the money and the trailer sits about 1/2" to 1" lower in front than in the rear (very slightly tongue down). The initial test drive was very good. The trailer tows straight and the WDH spring bars don't seem to impart too much bounce. I think that once we fully load the trailer for travel, I'll lower the L brackets a notch or two to see if I detect any difference in drive-ability.