Drive a wood wedge underneath the piece you want to remove and just to one side of a siding nail with a hammer. The wedge will provide a gap to enable you to insert a pry bar underneath the siding piece.
Insert the tip of a pry bar underneath the siding piece on the opposite side of the siding nail.
Lift upward on the pry bar to pull the siding away from the home. The purpose here is to expose the nail head by lifting the siding. Do not push down on the pry bar or else you may inadvertently damage the siding piece below the one you intend to remove. Remove the pry bar and the wood wedge once the nail head is exposed.
Lift the nail heads along the entire length of the siding piece using the same method.
Pry the nails out of the siding piece with the pry bar to release the siding from the home. Position the wood wedge between the pry bar and the siding piece you are removing when prying the nails out if you intend to reuse the siding piece. The wedge will prevent the pry bar from denting the siding.