Door Ajar light stays on

I was told it was a pin problem(door pin was missing). Since the light won’t turn off it is wearing down my battery. Is there an easy fix? Like cutting a wire or pulling a fuse? The subaru dealer is going to charge $300 to fix. Is it an easy fix if you have the part?

This car has several issues, so i don’t want to invest too much.

Thanks for your help.