If the .htaccess file is not writable, in order for WP Ghost to work you need to write the code you receive in the WP Ghost > Change Paths after you change the settings.
If you don’t have server access, you can install a plugin that will help you with this:
Htaccess File Editor – Safely Edit Htaccess File
You can remove the Htaccess File Editor plugin after you’re done configuring the WP Ghost plugin.