How to Swap Stages in SSF4AE

With a lot of new stages being backported from SFxT and some brand new stages from mugenlove100, Alff suggested I write a tutorial on swapping around stages. It's a very simple process but it requires a hex editor, which makes some people uncomfortable. I use the free and open-source Frhed, which is somewhat limited in functionality but is thankfully quite simple to use. As a general note, stage mods are often built from the Training Stage (abbreviated as TRN), but I'll be using one that started from the Brazilian Jungle stage, or BRA. For reference, here's a key that shows which abbreviations go with which stages:

Key image courtesy of Jaldaboath :)

So, to get started, we'll first want to make backups of the stage we're going to replace. Personally, I hate the Crumbling Laboratory stage, so I copy those files to a safe place. Then, take your stage mod files, in this case BRA.emz and BRA.tex.emz, and open them each in your hex editor, like this:

Next, use the find-and-replace function (the standard shortcut for this is ctrl+H; you'll have to do it in each of the modded stage files) to replace each instance of BRA (or TRN if the mod is based on the Training Stage) with the 3-letter prefix of whichever stage you wish to replace, in this case LBX:

Click the button to replace all following occurrences and it should pop up a message telling you how many instances were replaced (it's generally a much larger number for the ***.emz files than for the ***.tex.emz files, FYI).

Once that's done, just save it and close, then rename the modded stage to match the 3-letter prefix you just swapped in. In this case, I change BRA.tex.emz > LBX.tex.emz and BRA.emz > LBX.emz.

Now you just copy those modded stage files into your [install dir]\resource\battle\stage directory and overwrite what's already there. Just make sure you backed up those original files first, in case you change your mind later.

UPDATE: If you would rather not overwrite any of the files, there is a way to supersede the original stages in a non-destructive way. Instead of adding your modded files to the above directory, instead go to [install dir]\patch 1a\battle and create a new directory named 'stage'. Put your modded files in there and the game should use them instead of the originals. (thanks to Nemesys_Syndrome for the tip)

That's it. You're done. Now, go try it out and make sure it works :)