Depends on the firearm. Some are reversible ambidextrous and others can be circumvented all together. Youtube is the best place to look for these tricks. Some modifications will void warranty's, so be advised.

Hi Stephen, yes as most semi-autos have an ambidextrous or reversible safety design these days. However, I would look for something suitable from the factory as we are in a litigious society and any firearm "modification" could be a potential snafu to be used by unscrupulous lawyers. Of course, this advice is for "Self Defense" firearms only.