Here is a product installation guide in English:

Piston Kit Installation Guide

Important: Before starting the installation, please ensure you have the following tools and materials:

• Required tools:

• Socket wrench or ratchet and socket set
• Torx screwdriver (for 47mm engine)
• Phillips screwdriver
• Pliers or punch
• Measuring tape

• Recommended tools:

• Engine hoist or jack stands
• C-clamps
• Cleaning cloth

• Required materials:

• Piston kit (41mm or 47mm, depending on your engine type)
• Gasket kit (included in the piston kit)
• Engine oil (compatible with your engine type)

Step 1: Prepare the Engine

1. Remove the engine from the vehicle or scooter, if possible.
2. Disconnect the spark plug wire and any other electrical connections.
3. Remove any protective covers or shrouds to access the engine components.

Step 2: Remove Old Piston and Ring

1. Use a socket wrench or ratchet and socket to remove the old piston from the engine cylinder.
2. Carefully pull out the old piston ring and gasket from the piston skirt.

Step 3: Install New Piston and Ring

1. Apply a thin layer of engine oil to the new piston ring and gasket.
2. Install the new piston ring onto the piston skirt, making sure it's properly seated.
3. Install the new piston into the engine cylinder, ensuring it's properly seated and aligned.

Step 4: Reassemble the Engine

1. Reconnect any electrical connections, such as the spark plug wire.
2. Reinstall any protective covers or shrouds.
3. Tighten all bolts and screws in a star pattern to avoid over-tightening.

Step 5: Check and Test

1. Check the engine for any leaks or unusual noises.
2. Start the engine and check for proper operation.
3. Test ride the vehicle or scooter to ensure proper performance.

Note: If you are not comfortable with this installation, it is recommended to seek the help of a professional mechanic or the dealership.