Being this vague means it is an unserious idea
"Take down the cops". So you're suggesting we just shoot them all? Is that your idea of a not vague idea?
We do need some sort of police force, always. As much as they suck, some people will always suck, and you need an enforcement measure to help prevent theft, rape, and murder and remove from society those who commit the latter two.
I personally think taking over from within is viable