Very simple procedure. Goes like this.
1) Remove the magazine
2) Clear the weapon
3) Cock the hammer(I do this, it makes it easier to hold the slide open)
4) Open the slide until the shaft of the slide stop is under the notch on the left side of the slide.
5) Holding the slide open with one hand(it can be done, you'll figure it out) push the slide stop out.
6) Slowly let the slide go forward. If you cocked it the hammer will fall. Don't worry it's supposed to.
7) Push the slide completely forward and off the frame.
8) Remove the recoil spring and guide by pushing forward(towards the muzzle) and lifting up.
9) Remove the barrel by pushing forward and lifting up.
To reassemble;
1) Place the barrel back in the slide.
2) Place the recoil spring and guide back in the slide being carful to lock it back in the groove on the under side of the barrel.
3) Place the slide assy back on the frame. don't cock the pistol. As you push the slide back you have to depress the tabs on the frame in front of the hammer and let the slide ride over top of them.
4) Here's the tricky part. With one hand, open the slide about 1/8th of an inch. Put the slide stop in as far as it will go. Open the slide further until the shaft of the slide stop is under the notch on the left side of the frame. Push the slide stop in the rest of the way.