Here i post all you need to do that it very easy my friend...
-Your phone + usb cable
-PC + windows
-Android Flasher (you can download HERE)
-My splash screen (you can download HERE)
When you have all tools...
and when you phone is connected
with good driver (you can download HERE)
You must unzip AndroidFlasher.zip
and run AndroidFlasher.exe
click next, then select your devices...
(here you can flash what you want but now i just explan how to for splash screen)
Browse to find image of splash screen... (you need a .bmp in 480/800 with only 24bit)
Check "I'm already in fastboot" in your phone push power buton and go to fasboot...
when you are on fast boot click Flash!
when is ok your phone restart and you get a new slash screen
enjoy my friend...