Well first u would need a custom boot Animation of ur choice and with the same width and height for your device..... If u want one check this XDA page
Then u would need root browser apk which is available in the play store.....
Move the Boot animation zip file to system/media and place it der..(in root browser of course) and then hold ur finger der
Scroll and select permission
Do what is present on the first pic
Then reboot ur phone and see the magic happen... Isn't it easy well it can be made easier!!!!!!!
Download an app which is available in the play store called boot Animation which installs the Boot animation automatically....... Well here u go..... So more pics will help u so I will post them and guys this was my first guide will be taking out another one on how to make a boot Animation so pls help me if I have gone wrong..........
Pics for boot Animation app (2 and third pic)
I ain't a professional so pls guide me if I am wrong in this guide or stuff
.... I won't be responsible for bricked phones or dead SD cards or thermonuclear war￼
Just post ur questions below.........