Heavy Bag very hard on one side

Ive always just worked it out, but that takes a good month or two of constant pounding.

yaeh just beat the crap out of it with very protective gloves.

DO NOT attempt to pound out the hard spot. You risk injury to your hands and wrists. When bags get hard spots its usually because the fill inside has become compacted too greatly from being in the same position for an extended period of time. What you should do, is open the bag and check the stuffing material. You may need to pull out the fill in the bag, loosen it up, and then restuff it. If that doesnt relieve it, then you can restuff it with new material, or get another bag.
Once again, trying to pound out a rock hard bag is going to put alot of stress on the small bones in your hand and put you at great risk of injury

Update

A bit of an update. As my hands become progressively worse for the wear, I decided to step back and evaluate. Keeping in mind that this bag is my first foray into anything boxing, and I haven't done a lot of reading -- I was making two big mistakes.

First -- I wasn't wrapping my hands. I guess in retrospect that ****'s Sporting goods sales clerk was not the authority he claimed to me (I should have known better).

Second -- the gloves I bought initially were Century Heavy Bag gloves, a whoppping 10 dollars and almost no padding. And impossible to get on to boot.

So on my way home on Friday I stopped back in Dicks, asked if I could return the gloves, was informed that yes I could, so I bought some better gloves. Which when combined with my new handwraps makes a world of a difference compared to before.

Glad to hear that you picked up some handwraps, and better gloves. Without proper hand protection, your setting yourself up for a hand/wrist injury.

Make sure you read my post above about re-settling the fill inside your heavy bag,
and welcome to the boards!