By default phpmyadmin is installed on the path /usr/share/phpmyadmin and the apache configuration file is located in /etc/httpd/conf.d/phpmyadmin.conf. You just need to locate the file phpmyadmin.conf by the command vi /etc/httpd/conf.d/phpmyadmin.conf
Once it is found, open this file.
You will see the contents of the file as below just remove or comment the first two lines in bold.
#Order Allow,Deny
#Deny from all
Allow from 127.0.0.1
Then Restart the apache server.
service httpd restart
Once this is done, you should be able to see phpmyadmin working by pointing your browser to
http://ipaddress/phpmyadmin