1. Have some kind of way to use ADB shell on another device like a pc, either android dev toolkit, ADB by itself, or Sidequest Advanced
2. Put the folder with the full map somewhere easy, like the downloads folder this is important, copy this path WITH THE FILE for later
3. Find the path to the saves folder you want on questcraft, copy up to the /saves point in there and do the following command:
adb shell mv <source_file_path_on_device> <destination_path_on_device>