Like you mention, getting on a flat surface (with wheel chocks of somesort), and not using the brake, to avoid changing engine vacuum abruptly when it's in this delicate state. (mechanics.stackexchange.com)
Step 2: Place wheel chocks around the rear tires that will be remaining on the ground. (yourmechanic.com)
If it was me, I would buy the HF trailer with the 12» wheels, put a deck of 3/4 ply on it, bolt a front wheel chock to it, screw down some rear wheel blocks, strap it tight and pull the trailer. (mechanics.stackexchange.com)