Okay, I'll show how to replace files using the SSBB(NTSC-USA) as an example.
Let's say we replace Pikachu's motion file with Ganondorf's.
The data needed are:
FitPikachuMotionEtc.pac
817DCFF4: 00003A2C 34832B63 0039E8E0
FitGanonMotionEtc.pac
817DBBF0: 00001D15 30CA8FF4 0038B5A0
From the data above, the code would be:
077DCFF8 00000008
30CA8FF4 0038B5A0
077DCFF8 (1st data of the file to replace) + 4 AND 0x03FFFFFF OR 0x06000000
00000008 Always the same
30CA8FF4 0038B5A0 2nd & 3rd data of the file to replace with
In case of "two026.brres", the 1st line becomes:
077EF328: 00000008