How do we get out of the contract to sell our home?

You are permitted to get out of a real estate contract if the circumstances have drastically changed.  However, I would need to know where in the process you are.  Are you beyond the contingency date?  Is there a closing date alreay set up?  do you have a lawyer involved yet?  If you are close to the closing date, the buyers may specifically enforce the contract and make you sell the home.  However, if you can talk to the buyers about the circumstances you may be able to reach a deal where you return their deposit and any fees that they incurred.  I suggest that you hire a lawyer to review the real estate contract and determine the clauses that you may rely upon to get out of the deal.  I would need to see the contract to give you a definitive answer. 

You probably can't unless the buyer fails to meet or comply with some condition of the contract. For example, if they have a mortgage contingency that falls through either because they fail to get a mortgage or they fail to get one by the date indicated.  In such an event, you could legally pull out.

However, it the buyer meets all of their obligations, you may have to honor your obligation to sell.  A contract is a contract.  If you refuse to sell, the buyer may be able to force a sale by taking you to court (this is known as "specific performance").  Evenif your drasticallt changed cirsumstances are such that the court doesn't compel a sale, the buyer will almost certainly be able to win substantial monetary damages. 

Possibly, the property inspection has not yet been completed it will disclose some items that need replacement or repair.  If the buyer comes back and tries to re-negotiate with respect to such matters, just be as inflexible as possible.  The buyer will then have the right to cancel the purchase.

At this point you should contact an attorney in your area who can more fully explore this situation with you and apprise you of your rights under specific state law.  The closer to closing the greater the damages so you should contact one ASAP.