If you have a deep well jet pump there is no easy way to chlorinate the well. If you have a larger well with a submersible pump, it's not too hard. It is very important that what ever you do. After pouring the bleach into the well, chase it with lots of water to wash it off the pipes and wire. The running of faucets until bleach is smelled is a good method. And the longer you can leave it in the pipes, the better. Four hours is probably long enough, but longer sure won't hurt.
Bleaching the well may not cure the problem. If you have Fecal Coliform, you may find that your well is shallow or has a hole in the casing and surface water is getting in. If it's just Coliform, it may be that the well has been setting for some time with no use. Running the water for several hours will sometimes cure that problem.