Loading Screen/Login Screen

Hi,
I wanted to change the Loading Screen and Login screen of a Private server, can someone tell me how to do it?
(I downloaded for Loading screen a file, it works but i want to know how to do it myself so i add a pic of my choise :D)

40b1ccf1a42464d9f857b39e90c24fef1a92ce8e

I search it too i will make my own loading screen ^^

i already know which file to edit but i need a programm plsss
*\Lineage II\SysTextures\L2Font-e.utx
thats the file to change but i need an .utx file editor pls