Simple, really. Just download the attachment I've provided, then make a document with Microsoft Paint* and create the hud you want. Then, Goto File>> Save As>> Save it as a png file, (from the save as file dropdown list) but call it Hud*.dds, you cab change the name if you wish. Save it in your Files>>>Gamecore>>>Huds. Then, if you've done everything, take the downloaded script which you probably downloaded earlier, and change all the YOURHUDNAMEHERE to the name of the dds file you saved in Files>>>Gamecore>>>Huds. Attach it to an npc as a main script, or get it to be in a trigger zone. I put in a sound, if it doesn't work, choose a different sound.
*Can be varied. (Can use other programs like photoshop, etc.
Nah.