If you have the right tools removing your crank is a relatively simple and painless process. In this video we removed a square taper crank, also know as a cotterless crankset. These days there are many other varieties of crank connection systems, like Shimano's Octalink, or FSA's ISIS. But on the majority of older bicycles, square taper is what you will be dealing with and in my opinion performs just as well as all that gimmicky new crap. You just have to get out and ride!
After you've assembled the necessary tools the you're ready to remove the crank you can get started!
1. If you removing the right side crank arm, lift the chain off the chainring and rest it on the bottom bracket shell.
2. Remove the dust cover (cap covering the crank bolt). The tool you need depends on the variety of cap. Some of them will require an allen wrench, screw driver or, in this case, a Quarter does the job. Be careful because most of the covers are pretty flimsy. If you don't have one, its not really an issue, just maybe rub a little great on the crank bolt to keep it from rusting, if it is rustable.
3. Remove the nut or bolt from the crank arm! Remember to do this, I'm an idiot and forgot to do this one time and spent a few hard minutes wrenching the crank puller like crazy until I realized I was an idiot and hadn't removed the crank bolt. Most bolts are 14mm, some are 15mm or 16mm and some are allen head. Unscrew it in the normal direction and check the inside of the crank for a washer and remove it, some have it, some don't.
4. Check to make sure you have the right size crank puller. Crank arms secured by nuts require one type, bolts another and then you throw those crazy Italians (Campy) in the mix and you need another one. Just make sure it seems to go together correctly or it could result in an epic fail.
5. Lube up the spindle and mating area (i.e. where the crank pull screws into the crank) Get you mind out of the gutter.
6. Unscrew the center portion of the tool out as far as it will go, the thread the out part of the tool into the crank arm, make sure it goes in all the way and then slightly tighten it with a wrench. I was a little lazy on this part in the video, but its important if you don't want to rip out any of the threads you need to get the tool in as far as it will go.
7. Tighten the inner part of the tool into the part screwed into the crank until the crank pops of, sometimes you have to crank like hell, if you can postition the wrench arm and the crank so you can squeeze them together to get some leverage, or put a pipe over the end of the wrench for extra leverage. (If you have a pipe laying around)
8. Pull the crank arm off and remove the tool, then repeat on the opposite side!