I don't know about a switch, but one word of caution that applies to any car....when removing the battery, always disconnect the negative terminal first and get it out of the way, then proceed to the positive. The reason is that your conductive wrench will do no harm if it cantacts the chasis while removing the negative terminal. After it is disconnected, there is no electrical path should you make a ground while disconnecting the positive terminal.
This may sound elementary, but a lot of DIY's learn the hard way. Hope this helps!