How do I replace the battery on my troy bilt super bronco lawn mower.

Hi,
The machine cannot be looked up with the info given. If it is a rider, it is probably under the seat and possibly covered. Always diconnect the negative (-) terminal first and the positive terminal (+) last. Connection order id reversed with positive first and negative last. This is done in this order to try to prevent shorting aand arcing.Peace,
Clarke