To remove the safeties...
Cock the hammer.
Place the thumb safety about halfway between "safe" and "fire". (You'll have to hold it there with your fingers because the safety plunger will make it want to go to "safe" or "fire")
Pull the thumb safety away from the frame. (Be aware the safety plunger is spring loaded, but should not fly away if SA built the pistol correctly).
When the thumb safety is free, the grip safety will also be free.
Article with pictures of the safeties and stuff underneath