fallout4 Need help making a loading screen for fallout 4!

[mrmarf]

I am not new to using gimp for picture editing etc. i seem to be having an issue where i want to change the loading screen of fallout 4 to no avail. i have made a picture and turned it into a dds file, i have tried taking a pre-existing dds screen and imputing a pic over it to no avail, i am in need of help/tutorial on getting it to work. the only info i can find is to change the alpha configuration of the picture but they did not go into detail and that post was a few years old. i would like assistance please and i want to do this my self so i can learn and can do it by myself in the future if necessary.