How to upgrade php version on plesk ?

Sol:  You can simply upgrade the php version on LINUX PLESK server by using following steps
root@server [/] # cd /usr/local/src
root@server [/usr/local/src]#  wget -q -O - http://www.atomicorp.com/installers/atomic.sh | sh
root@server [/usr/local/src]#  yum upgrade php
root@server [/usr/local/src]#  /etc/init.d/psa stopall
root@server [/usr/local/src]#  /etc/init.d/psa startall
root@server [/usr/local/src]#  php -v
Done