Installing aluminum sliding windows starts with accurate measurements of the opening-width, height, and depth-to ensure a snug fit. Remove the old window carefully, clean the frame area, and check for level and square. Apply flashing tape around the rough opening to prevent water intrusion. Set the new window in place, using shims at corners and sides to plumb and level it. Secure with screws through pre-drilled holes into the surrounding framing. Foam insulation fills gaps without over-compressing. Apply exterior caulk around the perimeter for a weather-tight seal. Inside, add trim or drywall compound as needed. Test the panels by sliding them fully open and closed-adjust rollers if they bind. Install screens last. For replacements, many slide right into existing frames. Always follow local codes for egress or energy requirements. Two people make lifting easier for larger units. Proper leveling prevents future sticking or drafts. After install, check operation in different weather to confirm seals work. Professional help ensures warranty coverage if issues arise later.