To replace transmission bolts, first use a hydraulic jack to lift the vehicle, and then verify whether the bolts are located in an accessible location on top of the transmission housing before removing them and placing new ones in their place. If the top bell housing bolts or starter bolts are immediately accessible, remove them with an appropriately sized wrench.
OEM parts manufacturers such as Automotive Racing Products and O'Reilly Auto Parts offer customers access to transmission parts, including bolts for a wide variety of engine transmissions. O'Reilly Auto Parts offers performance transmission pan bolts manufactured by Mr. Gasket, while Automotive Racing Products offers bolt and stud kits that are application-specific, come in black oxide finished chrome or rust-proof stainless steel and can be driven with either a 12-point head or a standard hex driver.
Whenever removing bolts or brackets from a vehicle's transmission, make sure to mark their locations or to make a simple diagram that shows their original locations. This prevents parts from getting mixed together during reassembly. It can also be helpful to keep each type of material in a separate, marked container so that bracket bolts and nuts do not get mixed with shifter bolts and nuts or bell housing bolts. Create and label the containers before beginning work to ensure that pieces do not get lost.