It's recommended to consult a repair manual specific to your year and model Silverado. The manual will have diagrams showing the exact location and provide detailed instructions for accessing it safely. A Haynes or Chilton manual would be a good place to start.
Important Note: Working with brake systems requires caution and specific knowledge. If you're not comfortable working on your vehicle's braking system, it's strongly recommended that you take it to a qualified mechanic. Improperly working on the braking system can be extremely dangerous.