How to Upgrade PHP 5.6 to PHP 7.3.x Stable Release on CentOS 7 for VestaCP ?

In this tutorial I’ll show you how to upgrade from PHP 5.6.x to PHP 7.3.x , I’ve tested on production server before writing this tutorial and its just working fine without any issue.  Now go to yum repo directory and Check  remi repo is available for php73
Note: If you want use Presta 1.7.5 then use PHP 7.2 , Details : Link 1
For Apache : update to PHP 7.2.x & MariaDB 10.1
For NGINX : update to PHP 7.2.x & MariaDB 10.1

Go to Yum Directory:

# cd /etc/yum.repos.d 
# ll

Now install yum-utils, a group of useful tools that enhance yum’s default package management features. Yum-utils can be used for manipulating package repositories and additional package management operations such as enabling or disabling packages without any manual configuration by a system administrator.
You can install it as follows:

# yum install yum-utils 

In this step, you need to enable Remi repository using yum-config-manager utility, as the default repository for installing PHP.

# yum-config-manager --enable remi-php70   [Install PHP 7.0] 
# yum-config-manager --enable remi-php71   [Install PHP 7.1]
# yum-config-manager --enable remi-php72   [Install PHP 7.2] 

But I will use PHP 7.3.x

# yum-config-manager --enable remi-php73   [Install PHP 7.3] 

Now just run this command :

# yum update -y 

You’ll see php packages are getting updated, After the update process you need to restart Apache server/php-fpm-(nginx) and check the php version from by below mentioned command:

Troubleshoot
If php upgrade process fails (no update/nothing happens) or you upgraded previously from 5.6 to 7.0/7.1/7.3 then you need to run this commands to disable php 5.6/7.0/7.1/7.2 and check the repolist

# yum repolist
# yum-config-manager --disable remi-php56
# yum-config-manager --disable remi-php70
# yum-config-manager --disable remi-php71 
# yum-config-manager --disable remi-php72 

Install Some Plugins

# yum install php-apcu
# yum install php-opcache
# yum install php-imagick
# yum install php-snmp

This article based on
Link 1
Link 2
Link 3