Ok well 1-4 is fine. You didn't do anything wrong there.
Personally I have never edited the game's files directly with the unpacker, I always use Slipstream so I'm not sure if you did something wrong there or not. I would highly recommend just using Slipstream to install any mods you make or download though, rather then repacking them manually. It is MUCH simpler. So you can just skip 5 & 6.
If you have questions about Slipstream you could probably ask on the Slipstream thread, more people might be able to help you there.
I don't think it really matters what program you used to edit the files... I assume it was Wordpad, Visual C++, or something similar.
Here is what I do when editing the files:
But first... You are on windows correct? You will need to allow file extensions to be seen when renaming things if you haven't already.
Here's how to do that (this is taken directly from Microsoft's help website):
To show or hide file name extensions
Open Folder Options by clicking the Start button Picture of the Start button, clicking Control Panel, clicking Appearance and Personalization, and then clicking Folder Options.
Click the View tab, and then, under Advanced settings, do one of the following:
To show file name extensions, clear the Hide extensions for known file types check box, and then click OK.
To hide file name extensions, select the Hide extensions for known file types check box, and then click OK.
Ok, if you follow these steps exactly everything should work fine:
1.)In the file you are editing Delete everything except for the one event you are actually changing to simplify things. So the only thing that should remain in the file is what you posted above. (That way Slipstream only has to replace one event rather than all of them with an exact copy) (It is also good practice for when you mod more complicated thing later on. You only want what you're actually changing in the file.)
2.)Save the file as a NEW "events.xml.append" anywhere, temporarily on your Desktop is what I recommend. If you have to just manually changing the extension by renaming is enough.
3.)Create a new folder named "data" You can just right click on your Desktop and create one there using New....
4.)Place your new "events.xml.append" file into the "data" file.
5.)Create a new Compressed (zipped) folder in the same way as (3).
6.)Rename that folder to whatever you want to call your "Mod"
7.)Either copy and paste or drag the "data" folder into the Compressed (zipped) folder.
8.)Manually change the Compressed (zipped) folder's extension from .zip to .ftl by renaming.
9.)Place the Compressed (zipped) folder into the Slipstream Mod Manager's mod folder
10.)Run Slipstream's "modman.exe" and your "Mod" should appear in the list. Select it and press Patch.
11.)When you run the game you should see your change.
If this doesn't work there has to be something wrong with Slipstream which isn't unheard of. Try reinstalling it or try asking in the Slipstream forums.
I wish you the best of luck. I had a really hard time starting with modding this game, but once you get the basics down you get the hang of it and it's really fun.
IF YOU HAVE ANY OTHER QUESTIONS JUST SEND ME A PM.