Method 1: go into your inventory, search for 'worn', and then 'Take off' (or 'Detach') anything which seems to be your AO.
Method 2: go directly to the AO in your inventory and take it off.
Method 3: right click on the AO HUD display and select detach.
Speaking properly, the Animation Overrider is the script which replaces the default animations with the ones you choose. The ZHAO is a perfectly good AO: there's no particular reason I've ever found to change from it.
The animation overrider is NOT the same as the animations within the overrider.
(Now, of course, there'll be a bunch of people saying why their preferred script is better.)
You then pack the overrider with the animations you prefer. So you can run around and buy this walk from place A, that run from place B, this landing from place C, but that hover from place D, and install them all into your AO.
Many - perhaps most - animators offer prepacked AOs with a set of their own animations inside. This is handy for people who don't want to deal with hunting for the perfect animations & configuring their AO.
Some people use 'Animation Overrider' to mean the packaged set of both AO and animations.
If you're unhappy with the animations your av is using, you don't need to replace the AO, just the animations. But if you don't want to deal with configuring the AO, you can buy a prepackaged set.
So the question is:
* are you after good animations?
* are you after a 'better' script than the ZHAO (which is a perfectly good script)?
* are you after a good set of animations & AO configured for those anims?
Tell us which of those you mean, and we can help you better.
Also, tell us what is 'good' in an animation for you.
Is your Av particularly tall? Particularly short? Particularly muscular? Particularly fat? A 98-pound skinny weakling? Supermodel skinny? All of these affect how an animation will look on your av.
Do you want to move like a biker? Like a supermodel? Like a surfer dude? Like a Valley Girl? Like a harassed New York financier? Like a backwoods hick?
Of course, you'll also want to look at how an animation looks on your particular avatar. I've found that folded arms that look fine on my B-cup av go right through the tits of a Dolly Parton-esque av. Or hands that rest neatly on a wide-hipped woman are floating in space for a V-figured man.
Similarly, a walk that looks natural on a muscular male looks like a kid trying to walk tough on most women or skinnier men.
Look for details. SL doesn't let us have much control over expressions or hands, so we display character and personality in the tilt of the head, the angle of the body, the angle we hold a hand on. Look for an animator who does that - who tilts the head in a stance, who makes subtle changes in the angle hands are held during a walk. Look for a ground-sit that your avatar looks comfortable in, and where the body parts are held in a way which expresses your personality.
... heh. For someone who needs more info to be much help, I've said a lot.
(which is why I'm here I guess) but first things first I will go and figure out what I'm wearing and go from there.. I will take your advice on the ZHAO, that's the second time I've heard good things about it, I'm thinking I'll probably get a package to start..Thanks so much for taking the time to answer me