Need Help Coding in a custom GUI


I’ve recently created a server using the Deathrun server:

I’ve been wanting to change the GUI since the day I got it. I’m just wondering how to code my custom GUI into it.

Picture of the custom GUI I want in:

All the images (e.g. Health Bar, Death sign, Thing where Health Bar goes in) are all separate png images.

Help would be much appreciated.

Thanks, Fresh

wrong section,

Thanks, sorry