How to change the Redmi Watch 2 Lite strap?
The Redmi Watch 2 Lite strap supports quick release and can be replaced as follows.
Remove the strap: To remove the strap, press the removal button with your finger while pulling the strap outward with your other hand.
Install the strap: align the recessed part of the strap end with the main body of the watch, and hear a "click" to indicate the successful installation of the strap.
https://www.mi.com/global/support/faq/details/KA-07273/