Hi Joshua,
You don't mention which screen needs to be replaced, which is important because the procedures are different for the two different screens. Sorry to say iFixit doesn't have a guide to tell you how to do that, but there's a Spanish site called Nadie Me Llama Gallina that has guides for replacing both screens.
Main Screen:
[link|https://www.nadiemellamagallina.com/en/manuales/smartphones-1/zte-204/zte-axon-m-1074/pantalla-principal-9379|Manuales / ZTE Axon M / Main screen|new_window=true]
Secondary Screen:
[link|https://www.nadiemellamagallina.com/en/manuales/smartphones-1/zte-204/zte-axon-m-1074/pantalla-secundaria-9378|Manuales / ZTE Axon M / Secondary screen|new_window=true]
You can find a replacement screen on most of the bigger sites like Amazon, eBay and AliExpress. Here's another site that offers both for sale so you can pick which one you need.
[link|https://www.nubiamart.com/zte-axon-m-z999-amoled-display-with-touch-screen-digitizer-assembly-replacement.html|ZTE Axon M Z999 LCD Display With Touch Screen Digitizer Assembly Replacement|new_window=true]
Hopefully that will get you going. Good luck and let us know how it goes!