a. Click "Load Packet". (number "a" showed in the image). New window will appear.
b. Enter "Primo_EM_software_service+sw" folder and select "Walton_Primo_EM_W533_M00_S04S_150619" file (number "b" showed in the image).
c. Click "Open" (number "c" showed in the image)
After clicking the "Start", press the volume down key of your handset, and connect it to your computer with USB cable. Remember: Before connecting the handset with your computer, you must turn it off. Also notice that the battery has to be kept inserted.
Flash operation will begin, you will see this window:
Disconnect phone, open battery and reconnect again (If non-removable). Enjoy!!