Here's what I did:
Installed 20xx 4.05, then read through
this guide
Basically you'll need to do 2 things: Modify MnSchl1 (or whatever it's called) with DAT texture wizard to change the icon of the stage (this is just for aesthetic reasons, doesn't affect loading the stage).
Next, you'll have to use a byte replacement to load in the alternate texture. You're talking about Yoshi's Story (GrSt.dat), so what you'll have to do is open up Start.dol in a hex editor, then search for /GrSt.dat (or whatever other stage you're trying to find. Look out for line breaks too b/c they mess up searching for stages like Green Greens 64)
Once you've located /GrSt.
dat, note the offset for the
d in
dat; that's the character you're going to overwrite. In this case, it's located at 0x3DF746 (note that people write offsets with a 0x in front of them). Take that 3DF746 and plug into melee code manager's RAM address conversion (under the tools tab). The RAM address in this case is 0x803E2746. This tells the game which characters in the hex it should alter when the stage is selected
The next step is to hop down to the stage replacements section. I'm going to overwrite brinstar depths, on the first page, with an alternate Yoshi's story (just as an example). First, I'd hop down to 0x003F8D50 and replace the first 8 digits (00 00 00 00) with 803E2746 (the RAM address). Next, I'd replace the 00 at 0x3F8D48 with 09 (this forces the game to load yoshi story rather than brinstar depths). Finally, replace the 00 at 0x003F8D60 with 31 (Hex value for "1"). Now, when the stage loads brinstar depths, it will instead load yoshi's story. Thanks to the byte replacement it will load up GrSt.
1at (because you replaced that
d from .
dat with
1, 0x31 in hex).
Finally it's a matter of adding your texture hacked yoshi's story to the root. Rename the file to GrSt.1at (it'll show up as a .1at file; that's fine, it'll load properly). Make sure to uncheck "use game ToC" then rebuild the ISO.
This is by far the easiest way to do it IMO. Make sure to
read Achilles guide, it breaks down everything you can do with stage replacements. Hopefully this helped!
