Note: you need to get a license from RVSiteBuilder website.
Installing RVSiteBuilder:
# cd /usr/local/cpanel/whostmgr/docroot/cgi/
# rm -f rvsitebuilderinstaller.tar
# wget http://download.rvglobalsoft.com/rvsitebuilderinstaller.tar
# tar -xvf rvsitebuilderinstaller.tar
# chmod 755 addon_rvsitebuilder.cgi
Now open WHM, ->> Add-ons section ->> RVSiteBuilder Installer menu. Click RVSiteBuilder Installer to begin the installation process.