You'll have to desolder the broken switch and replace it with a new one
This particular model has mechanical switched and official razer switches are available on amazon for 3100 rs (36 pieces), but i would recommend getting a similar switch from meckeys and replacing it
The keycap isn't broken so try with twizzers if you can pull out the broken part of the switch
I'd call it good riddance. Razer switches are incredibly looked down upon by the mechanical keyboard community. As hitomi said, you're better off getting custom switches (not Razer) and soldering them on.