Most WordPress security plugins also provides you a feature to hide WordPress version number but when you only want to remove WordPress version without using any new security plugin having lots of more feature that you don’t need or you are already using from some other plugin then in that case the easy way to hide WordPress version number is to add version hide hack in theme function file etc.
But now by using new light weight WordPress plugin Remove WP version and shortlink you can hide WordPress version number, shortlink, wlwmanifest and RSD. Simply install and activate it.
The plugin revent netizens from knowing what WordPress version you are using via your HTML source and it also cleanups the unwanted WordPress generated header tags.