I3 Pro B GT2560 Firmware Upgrade

[malp]

I've only just finished building my 2016 I3 Pro B and on testing I found that the X and Z axes move in the wrong direction when I send the extruder home. I understand that I need to modify the relevant lines in the firmware but I just cannot understand the steps that I need to follow from the posts that I have found. This is partly due to the fact that the posts send you to each other in a loop as a source of instruction. Also, for me, they assume some knowledge of this type of hardware and firmware. I spent 40 years in IT but I'm struggling with this because it's outside my outdated experience. This is my 'progress' so far:

I've downloaded the Arduino 1.0.1 compiler and Marlin_v1 zip. I tried to do a compilation but it gave a compiling error:
core.a(main.cpp.o): In function `main':
C:\Documents\arduino-1.0.1-windows\arduino-1.0.1\hardware\arduino\cores\arduino/main.cpp:5: undefined reference to `setup'
C:\Documents\arduino-1.0.1-windows\arduino-1.0.1\hardware\arduino\cores\arduino/main.cpp:15: undefined reference to `loop'

Clearly I'm not properly understanding what I need to do, so I need an idiot's guide to updating the firmware on my I3 Pro B. Can anyone help?

[siam]

hi

where have you downloaded the Marlin_v1 zip ? here from geeetech or from marlin's website?

[malp]

From the Marlin website

[bang]

Maybe you can try the firmware from here:
viewtopic.php?f=20&t=17046

[RickTwyman]

Same compile time error.

This report would have more information with
"Show verbose output during compilation"
enabled in File > Preferences.
Arduino: 1.0.6 (Mac OS X), Board: "Arduino Mega 2560 or Mega ADK"
core.a(main.cpp.o): In function `main':
/Applications/Arduino.app/Contents/Resources/Java/hardware/arduino/cores/arduino/main.cpp:34: undefined reference to `setup'
/Applications/Arduino.app/Contents/Resources/Java/hardware/arduino/cores/arduino/main.cpp:44: undefined reference to `loop'

Tried Marlin both from Marlin site and from your reference below.
In my case I have assembled the delta G2 or G2s (how do I know the difference?) with the metal spider.

[malp]

My compilation from the forum link completed without any errors. On upload it corrected the X axis direction problem.