My power button needs replacing

I have an old Toshiba Satellite P55W-C5321-4K that still works really well, but the power button has sort of sunk into the laptop. I've opened up the laptop, but it looks like a small plastic piece that was attached to the back of the power button may have snapped/broken off at some point. Is there a way to purchase a replacement power button assembly or to have this fixed? I'd appreciate any help you could give me. I saw a question/answer about a slightly different model, but not for my specific model. Thanks