This is how to remove the battery from a Groove with no Keys and replace the lock core

Step 1: Remove the 3 Philips screws in the top cap

Step 2: Pry back the lock bracket to free to top of the battery

Step 3 lift up the top portion of the battery

Step 4 Remove the old lock core by removing the two philip screws and unplugging the port

Step 5 Plug in and reinstall new lockcore, following the above steps in reverse.