Um.... maybe something like this:
Cane Creek County Park, Union County, North Carolina, (April 2022).
The way this is done is to initially jack the trailer by the tongue jack as high as possible.
Then put blocks under the frame to where those blocks come as close as possible to the frame.
Now, lower the tongue jack and let the trailer rest on the frame.
Crank the tongue jack all the way up and now put a new set of blocks under the tongue jack.
Now crank the tongue jack as high as it will go again.
Now put more blocks under the frame as close as possible.
Keep repeating until you reach your level position.
Be sure your tires are chocked VERY well first.
Or.... in this case, they put those blocks under the leveling jacks, which will still work the same way. Just keep the leveling jacks collapsed until the very, very end, then use the stabilizing jacks to do the final stabilize.