1.) use openIV and navigate to mods\update\update.rpf\x64\data\cdimages\scaleform_frontend.rpf\

2.) backup the file "loadingscreen_startup.ytd" (there is also a standard backup version in this package)

3.) replace the file "loadingscreen_startup.ytd"

4.) thats it, lunch GTA V ;)

I will update soon, I will create a division of images to replace the original ones please be aware if you have any questions leave your comment with pleasure I will answer, if you want to suggest an idea I am open to them