This covers both Pronestor Visitor Selfregistration and Pronestor Visitor Reception module.
You can download the installation files here http://help.pronestor.com/download/
Direct link for Pronestor Visitor Reception module is here
Direct link for Pronestor Visitor Selfregistration is here
You can simply run the installation files on top of the existing installation to update the software.
You don't need to update your sql server.