1. Plan and prepare your surface: Before installing the veneer, you need to ensure that the surface is clean, level, dry, and free of any debris or loose material. If necessary, use a pressure washer to remove any dirt or stains. It is also important to ensure that the surface can support the weight of the thin veneer. If you're not sure, consult with a professional.

2. Apply mortar: After you have prepared the surface, you can start applying mortar to the back of the veneer. Use a trowel to apply a 3/8 inch thick coat of mortar to the back of the veneer, covering it completely. Make sure the mortar is evenly spread and covers the whole surface.

3. Place the veneer: Once the mortar is applied, gently press the thin veneer into place. Don't push too hard, as this may cause the veneer to crack. Start at the bottom and work your way up, overlapping the pieces slightly. Keep the joints between the pieces as narrow as possible to maintain a natural look.

4. Cut the veneer: If you need to cut the veneer to fit around obstacles or corners, use a wet saw or a chisel and hammer. Be careful when cutting, as the veneer can be brittle and easily break.

5. Allow drying time: After you have installed the veneer, allow it to dry for at least 24 hours before applying any sealant or grout. Make sure the veneer is completely dry before moving on to the next step.

6. Apply sealant: Once the veneer is completely dry, apply a sealant to protect it from moisture and stains. You can use a natural stone sealer or a water-based sealer. Follow the manufacturer's instructions carefully.