The steps and precautions for changing a hamster's wood shavings are as follows:
Safe Isolation: Before changing the wood shavings, make sure to safely transfer the hamster to another clean temporary cage with a small amount of wood shavings first. This is to prevent the hamster from escaping or getting startled during the process of changing the shavings.

Thoroughly Clean the Cage: Remove the old wood shavings. Use warm water and a mild detergent to clean the bottom of the cage and other accessories. Get rid of any remaining stains and urine marks to ensure that the new wood shavings are placed in a clean environment and avoid leaving too many bacteria in the cage.
Control Humidity: Before putting in the new wood shavings, dry the bottom of the cage to prevent the wood shavings from getting damp and moldy, which could affect the hamster's health.
Bedding Selection: Choose the appropriate bedding according to the season. In autumn and winter, you can select bedding materials with good heat - retaining properties, such as wood shavings and wood wool. In summer, choose bedding with good air permeability, like wood filaments, dried flowers and plants, or paper pellets.
Bedding Thickness: In summer, a bedding layer of 2 - 3 centimeters is sufficient. In winter, it can be laid thicker to help the hamster keep warm.
Pay Attention to Personal Hygiene: During the cleaning process, pay attention to personal hygiene. Avoid directly touching the bedding with your hands. Wash your hands after changing the bedding to prevent the spread of bacteria.
Frequency of Changing Wood Shavings: It is generally recommended to change the wood shavings once a week. In the hot and humid summer, it is advisable to change them every 3 - 4 days. In the dry winter, you can change them every 7 - 10 days. If you find that the wood shavings have become damp, have an odor, or are moldy, change them immediately.