BRC already answered this part: "Do you want to answer my question how to use "2007 General Journal Entry.iif"?"

The info is in the Kit. The coding instructions, example files, understanding the optional settings and providing required field info, that's all in the kit. There are instructions in the kit, as well.

How to Use it is: Code the file. Then, you should make a backup of your QB file, because there is no unimport. Then you use File menu > Utilities, Import and there is the tool to browse to the file you made.