Birds have taken over my garage-any suggestions?

I have tried to coexist with these birds, but they have taken over my detached garage. They are black birds and small brownish birds. I have 2 windows in the garage. The birds broke the glass out of several of the panes. I put some cardboard over the broken panes, and then staple-gunned some screen wire on the inside and outside of the window. The other window had large gaps between the window and the brick wall of the garage, so I put some of that "insulation in a can" around the window. The garage door has been closed for several days. Every time I open the door, birds fly out. I will say that this is a very poorly built garage. The interior walls do not go all the way up to the ceiling. It's like there is some kind of drywall-ish sheets, but there is a lot of space between the interior walls of the garage and the outer brick walls. I am sure that there are birds nesting in between the walls. When the birds fly out, they don't fly at me, but it is disturbing nonetheless. My daughter is terrified of birds, and you can hear her screams for miles when they fly out near her. I am sitting down in my basement and I can hear the birds outside from all the way down here. I do not even put my car in the garage anymore, because I don't want birds to fly out near me or my daughter.
I have read on the internet about fake owls, strips of orange tape, or cds hanging up to scare away birds. However, I think if I leave the garage door open, the birds will fly out, but then they will fly back in, as this has happened before. I am not sure how effective hanging those things from the rafters would be. Also, that would involve going into the garage and hanging around in there, with the birds tweeting all around me. I also don't know how effective bird netting would be, and besides, it costs a fortune.
I considered bug-bombing the garage, but I'm not sure that would work. I considered avian poison (okay, I didn't seriously consider it-well, just for a minute). I do not want to have dead birds or poison around because I don't want my dogs to be poisoned. I have considered burning down my garage.

I think if they would all get out, I could put some more screening on the window and make sure the door isn't left open, and then they wouldn't be in there anymore.

Does anyone have any suggestions for how to get these #$%&*# birds out of my garage, once and for all?

Ellen, there are a number of things your going to need to do from you telling.

First thing you need to do is make sure the structure is bird proof, closing all holes with wood, no gaps no holes, including near the top under the eaves. Next repair the windows with clear plexi, or install some steel grates across them. the kind you would find in the home security section.

Once youve secured the building, the only thing left to do is make sure that you get the birds out. you may have to climb into the rafters to insure that there isnt nests up there, mother birds will be pretty protective of you trying to get to their young. I would suggest a cat or similar disturbance factors, Ive heard of people leaving radios(playing whitenoise/static) can help drive birds away. Worst case scenario would be a lawn chair and a pellet rifle, and you having to sit in the garage with the door closed waiting for them to peek out.