# rustup component > Modify a toolchain's installed components. > Without the `--toolchain` option `rustup` will use the default toolchain. See `rustup help toolchain` for more information about toolchains. > More information: . - Add a component to a toolchain: `rustup component add --toolchain {{toolchain}} {{component}}` - Remove a component from a toolchain: `rustup component remove --toolchain {{toolchain}} {{component}}` - List installed and available components for a toolchain: `rustup component list --toolchain {{toolchain}}` - List installed components for a toolchain: `rustup component list --toolchain {{toolchain}} --installed`