As Strayhorn says, definately make sure it is unloaded (mag and chamber). Then pull back the slide about halfway. Where I'll add my 2 cents is that once the slide is pulled back halfway, engage the safety. That puts it in exactly the right position to twist the barrel so you can pull off the slide. Once the barrel is twisted, you can release the safety and the slide and barrel pop right off. The rest is pretty simple. Good luck.