With my whole wrong software on my abs module I ended up removing my abs module over 10 times.
I was able to remove the module from the car and reinstall a different module by removing the brake lines, it would take me a little under 10 minutes.

I can definitely confirm that it introduces some air into the brake lines.
Personally it didn't feel enough that the car was unsafe, but I love to have a rock hard brake pedal and spent the extra half hour bleeding the brake lines.