I have a single wooden garage door in my garage that is falling apart and would like to replace it for a new single steel garage door (with no motor). When I went to look for the same size garage door that I currently have I could not find it and had to buy one from Home Depot that is 7 inches smaller than the one I currently have.

The problem that I have now is that the garage door opening is about 7 inches more in height only (width is the same). Any ideas how I can do this myself?

Thanks!

Garage doors come in more than one height and I think you just bought the wrong door. You might be able to just add one more panel but not all places will sell just a panel.