1. Install java(http://www.java.com/en/download/index.jsp)
2. Make sure java is in your PATH. To test this, open git bash, and type "java". If it says unknown command, you need to add JAVA/bin to your PATH variable (A guide for this can be found at https://www.java.com/en/download/help/path.xml ).

Merging
The easiest way to do merging is to install the merge driver. For this, open `Baystation12/.git/config` in a text editor, and paste the following lines to the end of it:

[merge "merge-dmi"]
	name = iconfile merge driver
	driver = ./tools/dmitool/dmimerge.sh %O %A %B

After this, merging DMI files should happen automagically unless there are conflicts (an icon_state that both you and someone else changed).
If there are conflicts, you will unfortunately still be stuck with opening both versions in the editor, and manually resolving the issues with those states.