Part one: the tools
you only need Hexplorer for this, if you don't have it, get it at:
http://www.snapfiles.com/get/hexplorer.html

Part two: what we're modding
you need a save file to mod first, can be found in my documents\games\galciv2 usualy
also, you'd like to edit the save at the very beginning of the game, before anything is buildt. this is because buildings kinda mess things up a bit, you can still mod it though.

Part three: how
when you open the first save file for the first time you'll notice the numbers are small, to fix: go to view, select options, and try a different font, I'm using default GUI font
also see how many colums you prefer, I found 5 colums of 4 pairs fitting

first the order of tiles, you'd like to know where the tiles are located
6-12-18-etc.
5-11-17-etc.
4-10-16-etc.
3-09-15-etc.
2-08-14-etc.
1-07-13-etc.
nr.1 is the first tile u see, nr.2 the second

now you need to find your planet in there, its not too hard actualy.. I edited a planet named Spectre (to be neutral), next to the wall of numbers there is a decrypted version telling you what it says, the name of your planet should show up there.
Also remember that your star may have more planets with the same name, only with more I's behind (spectre II, spectre III)

scroll down from your planet there until you get to the lots of FF's, they are the tiles..
here's a sample of two unbuildable tiles followed by some buildable:

I marked two tiles there, blue and red is identical as you see, an empty tile has this length, with a collumn with 0's between, these 0's could be part of tile, but the game crashed when I tried it out.

beginning to look closer, you probably noticed the pairs of F's, they make the tile unbuildable, the 09 right behind it is what terrain the tile is, on the buildable tiles the F's are simply replaced with 0's, that's how easily you make a tile buildable
last, the line with "80 3F" is somewhere in the middle of the tile and seems to mean: absolutely nothing at all.. but it's a good thing to use to count to the tile you want.

the bonus
because of upload trouble I can't directly show you, but the 803F is again the place to look, see a tile with a bonus will look a bit like this:
00 09 00 00 00 00 00 00 41 00 00 00
the 09 is the location that gives the bonus icon, description and effect
the 0041 I lined gives you the bonus amount, the 0041 is acually located where the 803F used to be, so now you know where to do the change.
all you need to do to give a tile this bonus is to change these locations, remember how many 0's away the 09 is from the 803F-place, location means all

Part Four the values
icon location:
+700% production : 0A
+700% research : 09
+300% production : 08
+300% food : 07
+300% research : 06
+100% Influence : 05
+100% approval : 04

effect amount
+700% : 00 41
+300% : 80 40
+100% : 00 40
-50% : 00 3F

(it is possible to add a bonus to a tile with a building, but it's harder to know where to edit, again, 803F is the way to search, then just try, you can even add a bonus to your capital)

thanks to FROOKIE and Moosetek13 for a starting boost in my research



I should also notice that modifying save games will trip the cheater flag.

btw, I'm only having DL, so could a DA modder whos in for it grab the first one below for the DA codes.