Set a 4-foot step ladder next to a vinyl window in a room inside your house, about 2 feet away from the wall.
Slide open the window partially. Press in on the slider clips if they are still functional. Tilt the window in and lean it on the ladder. If the clips are broken and the window no longer tilts in, perform the repair with the window in place in the track.
Remove the screws that secure the latching mechanisms to the top of the window. Turn the screws counterclockwise to loosen them with a Phillips-head screwdriver. Remove the latches (there are usually two per window).
Pry around the edges at the top of the window where the latches were located using a putty knife. Gently work the top off the window with the putty knife. Remove the screws, if there are any, that secure the slider clips and remove the clips.