Factory tint is usually really light and blue/green, but it's 'in the glass' so you can't do anything about it.
If it's a film tint you want to remove then get a heat gun (hairdryer works too, but takes longer) warm the film on the inside of the window, then start on the outside one section at a time, once you're up to around 40° you'll find it fairly easy to get an edge going, keep pulling and warming as you go until you've pulled the film right off. Clean your window and you're done.
As for the black stuff - pretty sure that's not going to come off.