Closets are great for out-of-sight storage, but they reduce your living space. Fortunately, at least one of the walls dividing the closet from the rest of the room is always non-loadbaring. A non-loadbearing wall can be removed without affecting the structural integrity of your house. Knocking out a closet wall requires a little strength and a few tools, but no specialized skill.
Climb into the attic to determine whether the wall you want to remove is load bearing or non-loadbearing. A non-loadbearing wall will either run parallel to the ceiling joists -- beams running across the floor of the attic -- or will not have the end of a joist resting on it -- joists may cross it but their ends will rest on the exterior wall. If you don't have access to the house's framing, consult a building professional to determine whether the wall you want to move is load-bearing or non-loadbearing. Spending a few dollars on professional advice is much better than having your house fall in.
Knock a hole through the drywall between any two studs. Reach in and pull the drywall from the studs by hand. Remove all drywall from interior and exterior sides of the closet to reveal the wall framing.
Have a licensed electrician reroute any electrical wires and move electrical switches and sockets to a new location. Local business codes require that electrical work be permitted and completed by a licensed electrician.
Cut along the seam between the door frame and wall framing with a reciprocating saw. Remove the door and frame and set them aside.
Cut the wall studs midway between the floor and ceiling. Pull cut pieces from the top and bottom plates by hand.
Pry the bottom plate from the floor with a crowbar. Pry the top plate from the ceiling joists to complete the wall demolition.