Changing your Unreal splash screen is very simple to do, creating one maybe a little more difficult. To change your start up splash screen all you need is a bitmap picture of your choice sized about 536x480. Then just open your Unreal/Help folder and add it to the folder. 

Next you need to rename your logo picture to something like originallogo for back up purposes and rename the picture you want to use as your splash screen "logo" It's that simple, your replacing your old Unreal splash screen. 
With a new Unreal splash screen. 