How do I change the back tire on a mountain bike?

To change the back tire on a mountain bike, follow these steps:

1. Flip the bike over and loosen the bolts on the wheel axle using a wrench.
2. Remove the chain from the rear derailleur and lift the wheel out of the frame.
3. Deflate the tire and use tire levers to remove it from the rim.
4. Install the new tire onto the rim and inflate it to the recommended pressure.
5. Place the wheel back into the frame, reattach the chain, and tighten the axle bolts.
6. Test the wheel to ensure it spins smoothly before riding.