Legal Question in Real Estate Law in California

They sure can, if they can find someone who wants it.

Either giving it as a gift or selling it breaks the joint tenancy and the owners become tenants in common. Sending an e-mail telling the other joint tenant that you no longer want to be a joint tenant and as of a certain date will not be is also sufficient. But no one will want to buy at a reasonable price a property over which they must first get the agreement of the other owners before they can do anything.