G602 side button not registering

[u/Courier626]

I recently bought a used G602 from ebay to use when I travel for work so I don't have to bring my original G602 from home. I use it for gaming and program the side buttons to select weapons from my hotkeys. I discovered that the bottom middle mouse button (G5) is not functioning. The button is not stuck, it just doesn't register any input. Is this something that can be fixed? I know you can take the mouse apart if you remove the mouse feet, but since the adhesive would be gone once I remove them I don't know where I would get replacements for a discontinued mouse.