I don’t know why by our house has 10+ different kinds of light fittings!!!
And each with different types of globes!
On the most recent bulb I had to look up how to take the cover off. It was straightforward in the end but I didn’t want to pull or push in anything to hard incase the glass broke.
So here is how to take the cover off an oyster light from the 70’s (I’m assuming due to the age of the house.
Oyster light shade
All you have to do it pull on that clasp but if yours is anything like mind it might be stuff and hard to pull
Now be careful putting the cover back on. If yours is glass and the clasp springs back to quick you might chip it.