Changing a brake caliper is a task that requires some mechanical knowledge and tools. Here's a step-by-step guide to help you through the process:
Locate the brake caliper and inspect the setup.
Place a drip pan under the brake assembly to catch any brake fluid.
Use a brake line wrench to disconnect the brake line from the caliper. Be prepared for some brake fluid to leak out.
Remove the caliper mounting bolts using a socket set and ratchet.
Slide the caliper off the rotor. You may need to use a C-clamp or brake caliper tool to compress the caliper piston if it is tight.

Position the new caliper over the rotor.
Secure it with the mounting bolts, tightening them to the manufacturer's specified torque using a torque wrench.
Reconnect the brake line to the new caliper. Ensure the connection is tight to prevent leaks.

Open the brake bleeder valve on the new caliper.
Have a helper press the brake pedal slowly to the floor and hold it.
Close the bleeder valve and have the helper release the brake pedal.
Repeat this process until no air bubbles come out of the bleeder valve and only brake fluid flows. Keep an eye on the brake fluid reservoir and add more fluid as needed to prevent it from running dry.

Reinstall the wheel and hand-tighten the lug nuts.
Lower the vehicle off the jack stands using the jack.
Tighten the lug nuts in a star pattern to the manufacturer's specified torque using a torque wrench.

Press the brake pedal several times to ensure it feels firm.
Check the brake fluid level and top off if necessary.
Take the vehicle for a test drive at low speeds to ensure the brakes are working properly.
Always refer to your vehicle's service manual for specific instructions and torque specifications.
Dispose of the old brake fluid and caliper properly, according to local regulations.
If you are not confident in performing this task, consider seeking the help of a professional mechanic.
By following these steps, you should be able to change a brake caliper successfully. If you encounter any issues or have any doubts, it's best to consult with a professional.