How to replace php 5.4 with php 5.6.

Before installing PHP 5.6, apply any existing updates available for your distribution:

# yum check-update
# yum update

Also, this is a good moment to get (and save somewhere) a list of our installed packages (in case we need to rollback):

# rpm -qa |grep php
php-mbstring-5.4.16-36.1.el7_2.1.x86_64
php-mysql-5.4.16-36.1.el7_2.1.x86_64
(...)
php-gd-5.4.16-36.1.el7_2.1.x86_64
php-odbc-5.4.16-36.1.el7_2.1.x86_64

Download and install the “repos” package:

# wget http://rpms.famillecollet.com/enterprise/remi-release-7.rpm

# rpm -Uhv remi-release-7.rpm

Now enable the repository in Yum by setting enable=1 for the remi-php56 repo:

# nano /etc/yum.repos.d/remi.repo
(...)

[remi-php56]
name=Remi's PHP 5.6 RPM repository for Enterprise Linux 7 - $basearch
mirrorlist=http://rpms.remirepo.net/enterprise/7/php56/mirror
enabled=1
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-remi

(...)

Replace PHP 5.4 with PHP 5.6
Install the packages not as a Software Collection but as “Replacement Packages”:

# yum update

This yum update command should upgrade all our PHP packages. If it does not upgrade them or we don’t have PHP already installed, then do:

# yum --enablerepo=remi-php56 install php-cli

Yum will remove the old packages and install the new ones.

Now, restart services:

# systemctl restart httpd
# systemctl restart nginx
# systemctl restart php-fpm

if you receive an Nginx error, then you may need to reconfigure it. See: https://geekdecoder.com/install-nginx-centos-7/