How do you remove single pane windows and replace with double pane insulated windows on a existing brick home?

Read manufacturer directions thoroughly. Measure smallest height and width dimensions of existing aluminum window frame for rough opening at several locations. Order retrofit window 1/2 inch smaller on each side. Remove old glass and center aluminum stave. Trim fin of new window as little as possible so it fits against outside face of confined edges of outside facing part of existing frame. Drill holes in frame as manufacturer instructions dictate. Test fit window and mark where outside trimmed fin ends on wall. Measure for shims at gaps between new and old inside frames. Install shims with Lock time PL caulking. Caulk existing window frame corners, holes from removing center stave, and a 1/2 inch bead within the area marked on exterior wall. Place window and push into caulk. Make sure there is full contact with caulk. Drill pilot holes at screw locations drilled earlier, Place silicone caulking on screw heads and screw window in place. Square up window while screwing. Trim inside of window and plug holes from screws. Good luck.