Changing Wordress login logo and page background

I dont seem to be able to change the logo on the login screen using this plugin for some reason? I am unable to browse to any location (button does not work) and even if I typ in teh loaction and save the changes it just reverts back to the 'http://speciaal.co.uk/wp-admin/images/wordpress-logo.svg' url.

Also I'd like ot change the page background. How do I do this?

Thanks

AJ