theres no such thing as a stupid question! ask away if I can help no problem.
OK so yes you delete the tables in a database and views using phpmyadmin or mysql administrator or ..... there are loads of programs to do this.
In my installation I have a folder called connections which contains a file called installed.txt which lists the dat and time of installing.
I SUSPECT that when you run the install it checks and if it sees that file is effects the installation.