Your Hosting Account's PHP version can be changed at any time, in order to do that simply go to Websites → Manage, search for PHP Configuration on the sidebar and click on it:
On the newly opened page, you can select the PHP version you wish to use and click on Update:
How to select an older PHP version?
In case your want to use a previous PHP version, you can click on the Show no longer supported PHP versions button to display all the available options:
That’s it! Now you know how to change your PHP version for all your websites 😊
Additional resources: