mobile

Hi guys
Sorry for my first post being a help post !
I am a long time iPhone user and i just change to android and my first android phone is Samsung Galaxy Mega 2 (SM-G7508Q)
I bought this phone from china therefore it does not have google play store nor any google service !!!
I don't live in china so i rooted the device to install google service and play store and it works (mostly) but sometime i receive a message says google service has stopped and that really annoys after time !!
So i decided to install hong kong rom which allows google service automaticaly !!
I have downloaded 3 different firmware BUT !!!
when I try to flash them using odin I always receive the same error message !!!
volume size is too big odin invalid ext4 image !!!

I figured that the firmware size is really too big all of them are around 1,8 GB so downloaded a smaller size firmware which was 1,5 GB and the installation was successful (that firmware was also chinese one so no google service )
I really need to install one of the hong kong firmware but they are all big sizes !!
Is there anyone have any idea to how to solve that issue ??
how to solve volume size is too big odin invalid ext4 image issue !!
thanks for the help !!