If you want don't want your site to be managed by Installatron but still want to keep the installation of you site, you can follow steps below.
1. Login to your site's control panel, click on Installtron Applications Installer link. Click on the Wrench Icon of the installation that you want to remove that from Installatron.
2. Click on Advanced Tab
3. Scroll down to the bottom of the page, check "Remove from Installatron?" And then Click Save All.
4. You're done!