I've edited saved game files for countless games without ever looking at their code with a debugger/disassembler. It's simply not required for most simple edits. Unless the game uses a cryptic format or some kind of unknown compression (like the sheets vol) there is usually no need to resort to assembly.
The easiest way to edit saved game files, is to play, save a game, and write down the current value of what you want to change (like money), and then just search the saved game file for that value. Often you'll find exactly one place in the file with that value. If you find more than one, then you do this to a few saved game files and compare the search results. Usually that sort of thing won't move around in the file, at least not if you're always playing the same player (such as in singleplayer, when you're always the first player).
Sometimes you'll always have at least two possibilities. Like how money counters are made to move slowly. So there will be the actual amount you have, and then the current value displayed. Like how in C&C your money counter rolls towards your current value. If the value is stable, these two may be the same. Try editing the file to change them one at a time to see which is the real one, and which is the display one. (A backup of the saved game file is an especially good idea for this sort of thing. I once had a game delete a saved game file it thought was corrupt).
The bigger problem is if you don't find the value anywhere in the file. It could be the money is always a multiple of a certain value. In which case, divide by that value and search again. I think Warcraft II might have used that idea for the money in the gold mines. (Always a multiple of 100?).
It seldom gets more complicated than any of that. Although, if it does, there are techniques for the more comlicated ways too. Outpost 2 is simple though, in that it just stores the raw ore values into the file. A simple search and replace will do the job.
Btw, I've switched to HxD as my hex editor of choice now. I was having trouble loading large files under XVI32, due to it's use of virtual memory. It also seems to load the whole file when it was opened, which took a while for the larger ones. I don't have that issue with HxD. At any rate, either of the two can easily be used to edit ore in Outpost 2 saved game files. They're both free downloads. Just in case you don't feel like writing the dirt simple code to do the cheating yourself.