To install cPanl theme root login is required.Login into shell as root user and follow the steps
root@admin[~]# cd /usr/local/cpanel/whostmgr/docroot/
root@admin[~]#mkdir -p cpanelappinstall
root@admin[~]#cd cpanelappinstall
root@gunjan[~]#wget -q http://www.cpanelskindepot.com/skindownload/cpanelappinstall.tar
root@admin[~]#tar -xf cpanelappinstall.tar
root@gunjan[~]#rm -f cpanelappinstall.tar
Than browse following URL http://91.100.00.01:2086/cpanelappinstall/install.php
You can replace your server ip in above URL instead of 91.100.00.01 and follow the instruction
You done it