|Step1: Open xampp installation folder
|Step2: Rename apache and php folder
|Step3: Downlaod older xampp version from (https://sourceforge.net/projects/xampp/files/XAMPP%20Windows/)
|Step4: Choose your php version you want to downgrade/upgrade
|Step5: Dowload zip file
|Step6: Extract zip file and copy apache and php folder and replace to our xampp installation folder.
|Step7: Now open php folder and edit php.ini
|Step8: Find \xampp\ and replace with your xampp installation dir.( if C: and will replace C:\xampp or change as per your Dir.)
|Step9: Now start apache and mysql
|Step10 : Congrats, Check your upgraded/downgraded php version.