A deck is generally built as a permanent structure. Normally attached to the house with a ledger board and supported with posts sunk into concrete footings, at first glance it is unmovable. Either leave it where it is, or completely tear it apart and rebuild it in a new location. You can move a deck without quite as much fuss, however. First evaluate the size of the deck, considering that the larger it is, the more it will weigh. The more assistance you have, the easier it is to move the deck with virtually no disassembly. You can even move the deck on a trailer if the soil is firm enough to support the machinery. If all else fails, cut the deck into manageable sections and move in pieces.
Clear the deck surface of all items. Relocate the inventory far enough away to ensure an obstacle-free work area.
Disassemble the railing system. Loosen the balusters -- the thin vertical rails -- if they attach to the deck frame and unbolt the posts that run vertically on either side of the balusters. Lift the railings, whole if possible, from the deck for each side and set it aside for later reassembly.
Unbolt the deck where it attaches to the ledger board. This board, typically 2 inches thick, runs the length of the deck and is attached to the house with either lag bolts or through bolts that penetrate the entire depth of the deck frame and ledger.
Unbolt or unscrew the stairs where they attach to the deck. In some cases this will consist of simply removing the bolts and screws that secure the stair stringers -- the diagonally running stair step framing members -- from the deck joist. The stairs may then be pulled free in one piece. In some instances the stairs also incorporate footers and posts. If so, remove the posts before pulling the structure free.
Dig out the soil surrounding the posts to loosen them. Typically the hole is filled with concrete, in which case removal may be extremely difficult. Alternatively, cut the posts at ground level and install new posts if needed after the deck is moved. Ensure helpers support the deck during post removal to prevent injury or place solid blocks beneath the joists to support the deck instead.
Move the deck to the new location. Ask helpers to lift the deck -- now merely a large wooden platform -- and carry it to the new spot. Lowering the deck onto a large flat trailer is another option. A forklift can also lift and carry the deck easily. Use the method best suited to your situation, considering how much assistance you have, what equipment you have access to and the condition of your soil. If all else fails, consider cutting the deck in half, depth-wise. Cut between two joists and move the deck in two pieces.
Dig new footings as required at the new deck location. Follow local code determining depth and type requirements. At its simplest, a footer is a deep hole, created with post hole diggers, filled with concrete and a wooden post inserted. Use 6-by-6-inch posts and cut 1 1/2 inches away from two faces on the post to allow the joists to sit on the post in the recessed area, as well as bolting the joists to the posts.
Reassemble the deck precisely as it was disassembled. Bolt the deck to the posts and attach to a ledger board if the deck is secured to a building. Attach the stairs. Erect and secure the railing. If the deck was cut in half, add a new joist on either side of the cut to cap each piece in a boxlike construction. After adding the joists, bolt the joists together. Adding a new 6-by-6 post underneath the new connection will help reinforce the slightly weakened area.