So i have a 1991 honda accord with rear drum breaks and i want to make them disk brakes, i only know of the se models rear disk breaks but do any other fit? And how hard is it to change a system like that?

 

So... ignoring the curmudgeonly folk who would legitimately question the rationale for diddling with the most critical safety system on your car... realize from the git-go that this is will not be an easy job. And you're pretty much on your own since there's no model-specific procedure documentation. So how hard? Not easy hard.

But you can take some small comfort in the knowledge that a drum-to-disk swap has been done on plenty of makes and models and years of vehicles. Hit the YouTubes to get a sense of the chore that awaits. Search v6performance.net and Drive Accord against the most probable keywords to find posts by Honda-wrenchers who've done the deed. (There used to be a FAQ in this forum for this sort of swap, but it seems to have disappeared. ...probably for good reason.) Done yet? Still interested in perusing this chimera? Fine. Begin a parts list.

Prudence suggests sourcing used disk brakes—calipers, brackets, shroud, hat, parking brake, and other miscellaneous important bits—from a '91 Accord SE, but that's going to be some major wrenching. ('Course you could purchase aftermarket fresh, but my spidey-sense informs me your budget prohibit this.) You'll also need to grab the chunk of suspension (both sides, remember) that contains the caliper bracket mount points, and this will be no casual annoyance. You'll need new line. and the tools to bend and flare it. And you might need to replace the master cylinder up front and swap in compatible wheel hubs in back—but I'm admittedly clueless. Oh...then there's the ABS...

I kinda get the impulse here.
But bleh, little boy. Just, bleh.

Have you considered investing your resources on your education instead? ...or girls?