There are two separate questions here.  First, the mortgage:  the simplest way, if you can do it, is to pay off the mortgage first.  But depending on the value of the land, you may not have to pay the whole thing;  you might be able set it up so that part of what you get from the sale of the lot goes to pay off the mortgage, and in return the mortgage bank releases the lot you're selling from the mortgage lien.You may well need to get approval from the government to sell half the property; I'm sure at the very least something will have to be filed with the people who assess and collect your property taxes.  This might take time, and until you investigate, you don't know (a) if it's even possible, or (b) how much time it might take.For both of these questions, you need to get all the facts to a real estate lawyer in your area, who can give you reliable advice.  One place to look for a qualified attorney is our website, http://attorneypages.com