To replace outdoor patio screens, take off wood battens, and get rid of the old screening material. Attach base strips to the outside of the wooden posts, and put the new screening material in place. After that, attach cap trims over the wooden parts of the frame of the screen.
Old screen material is usually held in place by wood staples. One-by-2-inch wooden battens cover the staples, so remove them using a pry bar. After that, get rid of vertical 1-by-4-inch battens that are attached to the porch posts. Make sure to pound the staples flat after taking off the old screening material. First, attach vertical base strips that are a little smaller than the wooden posts. For example, 3 1/2-inch strips are suitable for 4-by-4-inch posts.
Attach base strips to vertical wooden bars, and remove the excess base material using pruning shears or tin snips. When attaching new screening material, make sure to hold it tightly with one hand while pushing it into the grooves in the base strips using a special tool. Trim the screening using a sharp knife. You may want to install stronger screening on the bottom parts of doors and windows so that it doesn't get torn by animals. Use a nonmarring mallet to attach cap trims, and attach wide pieces before the narrow horizontal ones.