How low can you go and why do you want to, or not.
The rules for a production bike , with few exceptions, require the bike be "OEM picture perfect" when presented to run.
Your objective to lower the bike is limited, but still possible within the rules.
You can actually cause the bike to settle down to the end of the suspension travel and do it within the visual rules you are held to.
Do you really want that ?
I think not.
You will do better with a little bit of suspension compliance until the perfectly flat earth is completely smooth, and still with good grip.
Lets just say for discussion purposes you have 4 inches of travel now and want to drop it to a minimum , but avoid the hammer you get when the travel bottoms out with a bump.
Stock shocks are really pretty good and well matched to the characteristics of the bike with some adjustment to suit the rider.
If the rear spring is exposed to scrutiny, you can collapse the end coils with a torch and that will cause the bike to sit lower if that is the objective.
You didn't remove any thing so it will pass the visual.
The added benefit is the remaining coils will be effectively stiffer, because the travel that remains is working on fewer coils over the same distance.
You can do the same with the front coils inside the forks.
Remember, you don't want to slam it to the bottom of the travel because it will slam your traction when you need it the most.
You can get away with a lotta stuff if conditions are perfect or you don't make enough power to get into the trouble you can easily fall off or into.