First things first in order to explore a save, you need to download an emulator. i recommend Visual Boy Advance for this as it can run any GBA, GBC, and GB roms.
Click open and select the corresponding rom for the save file. for this example i will be using Pokemon emerald using the save file located here
Next get to a point in the game where you can save, we will overwrite this with our save
The file we just saved is Emerald.sav and the file we downloaded is POKEMON_EMER_BPEJ00.
what we have to do is rename POKEMON_EMER_BPEJ00 to Emerald.sav.
you can select rename on the original file and copy the name. then delete it and rename the other file.
also make sure to have the file extension name as .sav and not .sv
now we should have a working save
