How can I get this asbestos sheet removed?
I have looked and never been able to find any data that indicates there is any measurable risk from a single, limited, isolated exposure to asbestos like this job would entail.  

Here is what I would do.  I'd put on a dust mask, cut it off with a reciprocating saw, maybe with a shop vac on it to pick up the worst of the sawdust.  

I'd put the cutoff in a garbage bag, empty the shop vacuum into the garbage bag, and tie the garbage bag shut while wearing the mask.  I might hose down the area.    

Obviously you would want to control the area to some extent so there's no kids, neighbors, etc. watching and being exposed to the dust.  

The hazard with asbestos comes when it's in the air and you breath it and you're exposed to it repeatedly over time.  The serious hazard is years of exposure, for example pipefitters and insulators that handled asbestos for years without protection had higher incidences of lung cancer, especially in smokers.  

It's not a direct analogy but it's like smoking:  it's dangerous but you are very very unlikely to get lung cancer from a smoking a single cigarette.  (Fortunately asbestos is not addictive so you don't have to worry that this one job will lead to two packs of asbestos a day for the next 20 years.)