Accidentally built my M3 laptop with system = "x86_64-darwin"; how can i rebuild it with system = "aarch64-darwin"?

Hello!
When I set up nix-darwin on my laptop many months ago, I apparently set system = “x86_64-darwin”. Everything works, but I would like to switch it to the native aarch64-darwin (it’s an M3 laptop).
This is the error:

error: a 'aarch64-darwin' with features {} is required to build '/nix/store/9v3qqh6nyc4psz7kcfi1239yqvgs2r9k-builder.pl.drv', but I am a 'x86_64-darwin' with features {apple-virt, benchmark, big-parallel, nixos-test}

I have tried adding:

nix.settings.extra-platforms = [ "x86_64-darwin" "aarch64-darwin" ];

but that didn’t help.
Is there a way to do this, or should i just give up and reinstall?

never mind, i might just be stupid.
i rebuilt with system=“x86_64-darwin”; and nix.settings.extra-platforms = [ “x86_64-darwin” “aarch64-darwin” ];
then i was able to change system to aarch64-darwin and rebuild