Just go to your phone's files then Android folder, LD's files should be on OBB folder and find the lustful desire's folder. If you cant find it, download "ZArchiver" on playstore and same thing find Android>OBB>Lustful desires>saves folder
Just copy the saves folder and thats it.
To transfer files if you already downloaded LD on that certain device, just find again LD's folder then then paste all of your save files inside the folder.