Easy way:

1. Go to WP Admin – Plugins – Add New.
2. Search for WooCommerce Custom Product Builder or Configurator – Especially PC Builder Toolkit.

3.  Install the plugin and then Activate it.

Manual way:

1. Download the plugin zip file.
2. Extract it.
3. Upload the plugin directory to wp-content/plugins.
4. Activate WooCommerce Custom Product Builder or Configurator – Especially PC Builder Toolkit plugin from WP Admin – Plugins.