If your decking boards need to be replaced it is really not that difficult. Start by removing the facia or edge boards that hold the decking boards in place using a crowbar. Remove the decking boards from the joists. Check the joists for dry rot while you have the decking boards off by poking them with a screwdriver. If the wood is soft and the screwdriver sinks right into the joist then you may need to replace that joint because it is dry rotted. When replacing the decking boards it is best to have staggered joints rather than straight rows. To do these start the first row using a cut board. Use cut boards to create a staggered pattern all the way across the deck. The cut ends must meet in the middle of the joist. The first board is nailed into the joist. The rest are attached using deck board ties. Nail the ties onto the edge of each board and slide it under the last board. Then toenail the board into the joist. The boards are pressure treated and resistant to rotting. The cut ends need to be treated with a wood preservative. Once the boards are all secure you have uneven ends on one side. Use a chalk line to make a straight cutting line down the edge of uneven boards and cut them all off at once using a circular saw. The last step is to protect the deck by applying a wood sealer using a hand sprayer.