Right in that case then, they are a push and twist.
The power pack on the back of the bulb also holds it in by two shaped clips either side, gently push it away from the engine, then twist is to the left as you look the direction the bulb is facing. you can then swap them over by gently prising the old one out (holding the bulb) and pushing the new one locating it so that the flat with the notch is located in the same place and using the base of the bulb to push it fully in. Then reversal of removing.
