How do I remove battery from hand held vacuum?

A battery for what ? Car battery are sold anywhere just make sure you have enough cranking Amps

U need a new battery it has a bad or defective one!

On WHAT?

Hi There,
Officially Electrolux don't want to sell the batteries so they discount the price of the hand held unit. Here in Australia they are called ergo rapido but it will be the smae everywhere I would assume. They will sell the battery on its own but it is more expensive than replacing the hand held part (without the filters) .

Check out the Electrolux's Floorcare site here and enter your address. They will show you the nearest location that sells the ZB266X and accessories:

http://smallappliances.electroluxusa.com/Customer-Support/Where-To-Buy/

I didn't understand what you need exactly, but anyway, you can find both of them on amazon (the entire vacum, or just a battery 1500Mah). take a look on following links:
1. entire vacum: Dyson DC16 Root 6 Handheld Vacuum Cleaner
2. just battery: Pwr 1500mAh Extended Capacity Battery for Dyson Dc16 Root 6 Vacuum Cleaner...

Most problems with what you have stated have to do with bad contacts between the hand held unit and the battery charger. With the charger unplugged, make sure the contacts on both the charger and hand held unit are clean and not bent. Check to see what the "Light Indicator" should be when charging and reinsert the unit into the charger. If the light does not show what it is supposed to show, move the hand held unit around a bit to see if you can make the connection better.
If this does not do the job, depending on the age of the unit, might be time to replace the battery.

I see my sense of humor is not appreciated...it was only a joke. Anyway, here is what you do: First, slide the battery cover off the bottom of the hand held unit. Remove the battery from the motor housing by pressing the tab on connector “A”; this releases the battery from the motor housing. Plug the new battery (LC-R064R2P) into connector “A”. When installing the battery the wires have to go in first and they must be placed in front of the battery or you'll never get the battery cover back on.