The error 403 is perhaps resulting on the fact that you have not defined the subdomain in your http server. You can use the "hello.php" to check that you have correctly configure the HTTP Server tool (ie cPanel, ....)
When you are sure concerning the subdomain name and the path defined in your HTTP Server that can be displayed with the "hello.php" see tutorial video 7.
Then you have the 2 parameters (domain) and (directory) that you have to provide in JMS definition.
You have to deploy the slave site in the same directory than the one you have defined in your HTTP Server.
It seems that was not correct that would explain the 403.
Cocnerning the installation directory you should not deleted it when JMS is installed.
Only the slave site can have the installation removed once the new installation is performed.
If this new installation is returned for your existing website, this is probably because you have defined it as a slave.
If the existing website is the "master" website, this mean that you have converted into a slave.
To access a master website, you can use any domain or subdomain that is not defined in the list of slave site.
So you could create a subdomain on your server that does not correspond to any slave and that is assigned to the same directory than your master.
If you want that we have a look on your server, we also provide billable support that can be ordered at
www.jms2win.com/download?page=shop.produ...35&category_id=1