I have a 2004 troy bilt 42" bronco rider with a 18.5 b & s engine. The brake switch is broken and I would like to know the best way to get to it to replace it. Thank you for your time.

Hi,
To get your own copy of the manual you will need the model# 13AJ609G766 and use just a 1 for the serial number. To get it got to:
PDF Manual Web Archive (http://manuals.mtdproducts.com/mtd/Public.do)
But I am afraid it is of little help with that switch. It seems that it has been moved toward the rear near the battery. This is an extremely large file of the 360 page service manual and pages 45 & 46 look to be the best.
http://www.mymowerparts.com/pdf/MTD_Service_Repair_Manuals/770-10579%20%20THE%20MUST%20HAVE%20MANUAL%20OF%20OUTDO OR%20POWER%20EQUIPMENT%20BOOK%202%20REAR%20ENGINE% 20RIDERS%20AND%20LAWN%20TRACTORS.pdf
Peace,
Clarke