Jiake A8 software upgrade

Be kind, I never done this before. But I'm looking for the update for a Jk A8 phone.
Or even better a great ROM for it. I'm trying to learn how to install a ROM but I do need an upgrade for my JK A8 phone. I have a HTC Desire 610 that I will be playing with. I will be looking around for some help on well the whole ROM install. I heard I need to install some thing like SP_Flash_Tool_exe_v3.1424.0.0 to flash the ROM.
I need step by step illustrations on how 2's.

Any kind help will make my month.

How to turn your Jiake M8 (6580M) into a G8 with 8Gb space

How to turn your Jiake M8 (MT6580M quadcore processor, 512Mb memory and 2 Gb space) to an Jiake G8 with 8Gb space.

First you need a rooted device.
If your device isn't rooted download Kingo Root here : click

Go to settings > security and turn on Unknown sources.
Then go to settings > Developer options and turn on USB debugging.
Now take out the battery but let the phone connected to the PC.

Download this files :
* Jiake G8 Firmware ( http://www.mediafire.com/download/j8..._G8_MT6580.rar )
* 4 Files that you need to flash after the first flash ( http://www.mediafire.com/download/q4...inal_files.rar )
* SP Flash Tool at http://spflashtool.com/

Start up SP Flash Tool , select the scatter file inside the Jiake G8 firmware folder and choose "firmware update".
Now press the download button and put your battery in your phone.
Wait for a circle saying "Ok".

Try to start your phone : it won't :) You will hear startup sounds and you'll see al kind of stripes on the screen.
Now take your battery out again.

Restart SP Flash Tool and select the scatter file in the G8 firmware folder again.
Now deselect all execept : boot.img , lk.img , logo.img and recovery.img
If you have done that change the location of the files to the folder with the 4 files.
Choose again for firmware update and press download.
Now put your battery in your phone and let it flash and wait again for the circle with "ok".

Turn on your phone and see :)

Warning : do not try to replace the 4 files into the folder of the G8 firmware, for some strange reason it won't work !

I did try this with 2 phones and everything was ok, so why not helping other people ? :)

Password for the rar files : gammapooka