Unlocking The E27 Lampholder
All ES & SES lampholders have a locking device to stop them coming apart when you take a bulb out.
Below is an image showing our inserts and what to do with the barb to release the lampholder, note some press down and others bend inwards.
With the ones you bend inwards you will need to ensure you bend the barb back before locking the lampholder again.
With all the locking devices you need to use a small screwdriver to depress or bend the barb whilst holding the base and turning the skirt or body of the lampholder anticlockwise.
Ensure the lampholder is not connected to the electricity.