You just have to fit the ambi safety, if you don't have a jig you can cut it with a file. But be warned the thumb safety is not just for looks it is a critical part to make sure the pistol is safe. You can easily over cut the safety ruing 50-75 Dollars. When I fit one, I have to take the pistol apart dozens of times, test fitting. I would give you the advice let a professional fit the safety for you.
And as mentioned sometimes an ambi safety has an arm that rides underneath the grip panel That also needs to be changed out or cut. Others use a sear pin to hold it in place.