This covers both Pronestor Visitor Self-registration 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 Self-registration 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.