If you have a five speed its easier. If you have an automatic you gotta use an impact gun or a chain wrench to hold the crank pully tight to use the breaker bar.

For Five speeds.

I usually put my socket and breaker bar on the bolt, put the breaker bar up against the front of your upper cam mount. So its pretty snug,

This step is harder without a friend but I can usually do it myself if the car is on flat ground. Try to have the car on pavement so your tires can get good traction. Put the car in neutral, then push the car in reverse untill you get some good momentum, jump in the moving car and push in the clutch and jam the car in 4th or 5th gear, pop the clutch while the car is still moving and your crank bolt should break free.

This is how ive been doing my friends timing belts on eclipses, civics, integras and my car and I havent had any problems with getting them loose. And it shouldnt damage anything, as long as your breaker bar is up against your cam mount, I usually try to have a friend help me push and they hold the breaker bar for me so it doesnt slam into my mount or the wrench fall off. (Just keep your fingers away!!!) I read it out of a repair manual for some import I was working on. And its pretty helpful when your doing a road side repair on a water pump or timing belt!