Should be noted that if you use 3DSMax - 2016 required! - you can use TaylorMouse's M3 import script. Also install SC2ArtTools - we have pinned messages in the Discord for download links. After you make your edits, use SC2ArtTools (when installed it will be a top right menu option) to export it back out using the Export Floater from the menu's dropdown. Just tick Mopaq Paths in the export popup to make sure texture paths remain internal to the map or mod file.
If all else fails I can just send you a blend file or max file with whatever model you need to print, but BaneBirst explained the Blender side really well so you should be fine :)