no this is pretty much impossible unless you send it to a specilist !
Sure if want it to be black afterwards. i suggest you seek professional help i you want it to stay light brown.
NO
no, it does not. a light colored jacket or a black jacket will go better with black pants.
I don't think it is possible to colour finished cashmere jacket at home.
by black dye\
No. Do not mix brown with black.
a black jacket
It will go Black
You can dye it
You can dye it with hair products or you can bleach it
black and brown
depending on the dye, it may go to dark brown or black. if it does go black, within a week or two, it may fade to dark brown.