Login to your account at https://rvglobalsoft.com/clientarea/. Under "Services" -> “Licenses”, click at the license you want, click "Change IP". After new license updated, you will get 15 days free license for the old server.
Please be noted that, only Active license can be transferred. 

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RVskin
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1. Transfer rvadmin hosting account from the old server to new server using WHM /Transfers.
2. Install RVskin in the new server using installation here: https://rvskin.com/rvskin/installation/

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RVsitebuilder 
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If server IP and physical server are changed.
1. Install RVsitebuilder on the NEW server, follow the installation:

RVsitebuilder 7 : https://rvsitebuilder.com/installation/

RVsitebuilder 6 : https://rvsitebuilder.com/v6/installation/ 

2. Make sure the transferring hosting accounts have moved from the OLD to the NEW server. You can move it using cPanel/WHM transfer facility.
3. On the new server WHM (root) -> Plugins -> RVglobalsoft Manager -> RVsitebuilder Manager, go to Recovering Projects. It will show the list of hosting accounts which contain RVsitebuilder data. Click the icon to access to their individual cPanel and go to RVsitebuilder. You will find the Missing Project Recovering dialogue. Just check the checkbox in front of the project ID and submit. It will restore RVsitebuilder project on this server.

If server IP is changed but physical server is not changed.
1. SSH to your server as root and rename the main configuration file at /var/cpanel/rvglobalsoft/rvsitebuilder/var/MAIN_SERVER_IP.conf.php and MAIN_SERVER_IP.default.conf.ini.php (if exist). Change the name to your new main IP.
2. Refresh the license key by accessing to WHM (root) ->Plugins -> RVglobalsoft Manager -> RVsitebuilder Manager. It will update your license automatically.