Can't change the page where to install

I purchased Ultimate Facebook for my site idniyra.eu. Now I got problems in conjunction with an other plugin. To figure it out I want to run your plugin in an other WP setup. I deleted Ultimate Facebook on idniyra.eu and tried to install on idniyra.eu/testpress. I got the message that I have reached the max of installable sites. BUT!!! I disabled the site idniyra.eu in your settings!!!
Need help in two problems:
1. How to switch Ultimate Facebook to another WP install for testing and after testing back again?
2. How to run the website parallel with Ultimate Facebook AND the plugin "CP Google Maps"?