Replacing mouse feet will not void a mouse warranty.
On the other hand, opening a product, removing the screws, and replacing parts can void a warranty.
If you wish to open your mouse to clean it, repair it, or replace parts you must first contact your seller for authorization. Although this will depend on your seller and their warranty terms, generally you can get authorization to open your mouse without voiding your warranty.
However, if you break anything during the process of opening the mouse and related operations, this may not be covered by your warranty. Therefore if you have an issue with your mouse, you must report it and request authorization before attempting to repair it, because it could be considered as caused by the operation.
If you purchased from one of our stores, please contact us by submitting a ticket, send us an explanation of why you wish to open your mouse, and we will get back to you shortly.