remove all traces of some files

I have been adding build files (.dll and .so files) to my git repository periodically when I have been doing builds of my project. I know I shouldn't be doing this and want to set up some other kind of separate archive or something for built files.

Although there are other devs on the project, I am the only one using Git. Everyone else uses AccuRev. Personally, I maintain my own Git repo (with an AccuRev git branch).

I would like to remove all traces of those .dll and .so files if I could in my git repository. I realize this would mess with hashes and would ultimately result in a completely new tree. I am fine with that since, as I said, I am the only user of this Git repo.

So, can this be done? Can I rebuild the tree preserving commit messages, timestamps, etc but ignoring certain files?

Thanks, ~Eric