People have posted the steps to do it. It’s not very hard. But if you are willing to strip the airtag to bits, it would be easier to plant a cheap android with a sim in someones car.
The point is that stalking has always been possible, it’s only important that apple doesn’t make it way too easy. Also when you find an airtag you can bring it to the police and they can get apple to give the owners details. Removing the speaker shows proof of intent.