I chose to install the latest version for CentOS 5 available on http://site.icu-project.org.

make sure we have the developer packages needed for procedure

# yum -y install php-devel php-pear

download and unpackage tar which code for relevant ICU lib version

# mkdir src
# cd src/
# wget http://download.icu-project.org/files/icu4c/58.1/icu4c-58_1-src.tgz
# tar zxf icu4c-58_1-src.tgz

build and install the library into /opt/icu4c-58_1

# cd icu/source/
# ./configure --prefix /opt/icu4c-58_1 && make && make install

build and install the php-intl version
enter /opt/icu4c-58_1 at prompt for ICU library location

# pecl install intl
# ldconfig

add an ini file wity contents: extension=intl.so

# vi /etc/php.d/intl.ini

you can now check to see if it’s loaded

# php -i | grep intl

restart the apache web server and you’re good to go

# service httpd restart