Measure the garage door panels and choose insulation material that fits the door type
Clean the door surface thoroughly and let it dry
Remove any loose hardware or damaged weatherstripping
Cut insulation panels or rolls to size
Attach insulation using adhesive, clips, or fasteners made for garage doors
Press the insulation firmly into each panel
Seal gaps around the edges with weatherstripping or garage door sealant
Insulate the garage door frame and threshold if needed
Recheck door balance and opener function after installation
Replace or adjust springs if the added weight affects door operation
Test the door for smooth opening and closing
Inspect the insulation periodically for wear, moisture, or detachment