BT Aqua Cordless Phone - Battery Compartment ???

[dal5band]

How the h!!! do you open the BT Aqua phone to change the rechargeable batteries. This is the small white cordless phone where the keyboard slides down. How do you get to the batteries (2xAAA) - is the white bit at the back that comes off or is the blue bit on top that comes off ?
It's obviously stuck but it would help if I knew which bit to push !!

Thanks in advance

 

[dal5band]

Done it !!! It was stuck due to leaky battery - someone had put alkaline batteries in the phone.
Needed a screwdriver and brute force !!