The new software update is available via OTA (over the air), and it weighs in at around 1.8GB in size. You probably need to connect to a fast Wi-Fi network and also charge your battery to at least 80% before proceeding with the software update. This Update will be Pop up as Notification on your device, So Be Patient
But Still The same Anyway If you feel impatient, or can’t wait for the update to arrive on your S2 Pro via OTA notification, then you should check for the update manually by heading over to your Handset’s Settings > About Phone > System update. You Can Check Yours If You Are Inifinix S2 Pro User, Although More Updates are to be Rolled Out On Other Infinix Model Smart Phones By March 2017.