Please contact your host provider ssh as root to server and run.

For cpanel
pear install -f /var/cpanel/rvglobalsoft/rvsitebuilder/scripts/RVSeagullMod-1.0.1.tgz
perl /usr/local/cpanel/whostmgr/docroot/cgi/rvsitebuilderinstaller/autoinstaller.cgi

For directadmin
pear install -f /usr/local/rvglobalsoft/rvsitebuilder/scripts/RVSeagullMod-1.0.1.tgz
perl /usr/local/rvglobalsoft/rvsitebuilderinstaller/autoinstaller.cgi