Battery Isolator switch

[aquadave]

I have a 1930 Model A with 6 volt positive ground system.
I have to take the fuse off of the starter as soon as I shut the engine off or the battery will drain.
I want to install a battery isolator switch but can't find a good drawing of how it should be installed in this system.
I'm planning on installing the switch at the base of the drivers seat just behind the access to the battery.
I'd really appreciate some help with this.