[Graphics] replacing battle backgrounds and great marsh graphics in pokemon platinum?

hello! so i'm a complete novice at rom hacking (especially nds) but i've been poking around with pokemon platinum with various different tools, and i just can't seem to figure out how/where to change the battle background graphics or the great marsh-specific graphics (as in, throwing mud or bait.)
i'm guessing the great marsh graphics have something to do with moves, but i have no idea where to find those, and as for the battle backgrounds i found battle/graphic/batt_bg.narc and battle/graphic/pl_batt_bg.narc, but both of them are just full of a whole bunch of .bin files and palettes, and if i unpack the .bin files using tinke i can't really make heads or tails of what i'm looking at anyway.
i've done some looking for tutorials but i haven't managed to find any, but if there's some around that i've just overlooked please let me know!
i really hope i'm not doing something wrong, i don't really know how to properly ask people for help, and i kind of only made this account for this thread...