Yes, i've already read the sheldon brown article, but i didn't really find it very helpful. Would it be possible to take them off by hammering the pin out and then maybe taking a hammer and a screwdriver or something and trying to knock them loose? And before i do this i should probably ask, would i be able to put regular cranks from my other bike on it, or do cottered cranks have different type of BB that they wouldn't fit on. Sorry for vague questions

From my understanding, the spindle is different. First off, what do you mean by regular cranks, square tapered? If you are lucky, you might be able to salvage your bb cups and get a square tapered spindle that fits. As far as the cottered cranks are concerned, if you hammer them out, make sure you support the arm somehow or you could risk damaging the bb shell.

What kind of bike is it?

my current ride is an early 90's schwinn world sport, the bike with the cottered cranks is unknown cause it has a custom paint job on it. It would be nice to be able to take off the cottered and put my cranks from my current bike on it, but if that wouldn't work I'd swap the BB too, if they're the same size.

Remove the cotter, then bang the cranks off with a BFH. (big ****ing hammer) You may have to hammer the cotter out.

You'll need a square taper bb spindle or a whole new bb to prelace the cottered spindle/bb.

You will need to change the BB.
If it's an older frame possibly a french frame the threads may not be the same so double check it.

yup big hammer knock out the cotter and then try turning the crank arm on the spindle it is the easiest way to get em to break loose also a lil wd40 goes along way the metal tends to rust /oxidise in there and make removal hard

Make sure you hammer them straight out - if you bend them, you're entering a world of pain.

Getting the cotter out is the hard part. Try to get it out in one big whack like Sheldon says. Support the bottom side of the crank with a pipe on the ground, so the bike doesn't have to take the stress, and just line it up perfectly and hit it as hard as you ****ing can. Once the cotter comes out the crank shouldn't be hard at all.

i tried to do this once, ended up effing the cotter pins on both sides. Had to drill out the cranks, which is no fun at all.

I'd say call around and bring it to a shop. Worth the $5.

save the bb lock ring. same thread as cog n can use it as a lock ring on conversions.

take apart an old crap pedal, and use the spindle to hammer out the pin instead of a screwdriver. you will break your screwdriver long before that thing budges.

we have a Var cotter pin press at the bike church.

This has been my experience as well. I whacked on the pin, and bent it right over. If you do end up drilling it out, use a new bit, a low-speed drill, and lots of machine oil.

usually all you have to do is get one arm off you should be able to get in there with a lockring tool and some channel locks and take the bb out then just slide it out and throw it away or keep the left side and make it into a chainwhip

I just converted an old frame to square tapered from cottered. Really easy. Took out the pins with one big wack of a regular hammer (don't use a mallet). The cranks came off easy after that. Then I just measured my bb to find out what size spindle I would need. used the orginal cups and a new spindle. Worked fine.