The first thing you need is a previous WordPress release. You can download any of the previous WordPress versions here: https://wordpress.org/download/release-archive/. Only downgrade down to the version before the newest one. Don’t go way back into the archives to version 1.1. Some of the older versions of WordPress have security issues that could put your site at risk.
Here’s how to downgrade WordPress to an older version.
Step 1: Deactivate All Your Plugins
Step 2: Logout of WordPress
Step 3: Login to Control Panel. You can also use FTP
Step 4: Delete The WP-Admin and WP-Includes Folders including .php files and other WordPress files of root directory of WorPress. Do not touch the wp-content folder!
Step 5: Login to your WP Dashboard. You will be prompted to update your WordPress database. Click on “Update WordPress Database” and then click continue to login.
Once you’re logged in, you should see that you’re running whatever version of WordPress that you downgraded to.
N.B. Do everything at your own risk. This article is a guideline only and does not provide any guarantee.