Failing that Wayne,
I wrapped a rag around the shock, took a gentle hold with some channel locks and turned the pre-tensioner.
Our two hondas have model specific shock wrenches.
You can put the scoot on the center stand, unbolt one shock and get both hands on it to turn, then re-bolt and do the other side. Heavy gloves work to grab that starred area.
Apparently, some yrs ago, these tools came with each bike/scoot.
Stig