Yes you can! I just did today. You need a philips screw driver.
If you have the white ion Block Rocker, find the access panel to the battery on the side of the device, (Facing the speaker it's the side to the left).
I suggest using a kitchen counter, island, tool bench for doing this job.
1. There is a simple 4 screw access door. Find it (opposite the side that has the charge lights and power switch).
2. Remove the screws, put in cup or saucer.
3. The door itself is super tight fitting, and you will need to turn the box on its side, battery door facing down, and gently bounce/tap/knock the device to work the door out were you can grab it with finger nails and work it open. (Gentle and patient but purposeful drops from an inch or so, no more, checking each time to see if the door opens. You don't want to damage the equipment. Pull out door and set aside.
4. Battery is also super tight in the access and suggest the same method until you can get some fingers on on the battery and work it out. I had to uncouple the horseshoe connectors + and 1 from the battery before i could pull the battery completely out.
5. Go to Battery PLUS, or Radio Shack with the battery in hand, to ensure you get the right one. SIZE MATTERS IT MUST BE EXACT. get a new one and RECYCLE THE OLD BATTERY with the store.
Follow reverse order to install.
Good Luck and let me know if it works. Dave S. Show Less