What to do first:
1) Save everything.
2) Take out SIM card.
3) Take out Micro SD.

What you need:
1) Firmware.
2) Flashprogram.
3) Flash cable (Original USB cable)
4) Your phone: S3370.

Lets Start.
1) Start with a hard rest for safety. (code *2767*3855#)
2) Check your firmware (Code *#1234#)
3) Check our firmware list and download a firmware you want. (We use S3370XEJD2)
4) Download the flash program. (Multiloader v5.63!)
5) Unrar the firmware.
6) Unrar the program.
7) Into the Firmware you will see three files. (Our ReadMe, CSC and CODE)
8) Open the multiloader.
9) Set a check by Boot Change.
10) Click on Boot and go to the Boot file and click.
11) Set in multiloader a check by All Download.
12) click on Amss and go to the file.
13) Do the same by Rsrc1, Rsrc2, Factory FS, CSC, SHP SPP and PFS.
14) NOTE select by RSRC2 always the LOW version!
15) NOTE check FFS and PFS on the same region. (We use SER)

16) Take you USB cable.
17) Take your phone.
18) Put your phone in Download MODE.(Sound Key Down + Camera + Power On) (Make sure your phone is out before)
19) You will seen now: DOWNLOAD MODE or ALL DOWNLOAD or BOOT change.
20) Take your USB cable and put him in youre Phone and PC.
21) Let the PC first install the drivers.
22) Go to multiloader and click on Port Search.
23) Wait 20 sec.
24) If he is ready click on Download.
25) Don't do anything now. (After the update he will be on agian.)

26) Congratulations, Your update is fine for 100%
27) End the flash thing with a hard reset. (code *2767*3855#)
28) If youre phone start again wait and shut him down normally.
29) Put you Simcard and your micro SD back in.
30) Your phone have now the last firmware and is 100% up to date.