How can I take off the pump on my zanussi fla1001w washing machine?

I have a zanussi fla1001w washing machine. My wife washed some curtains and some of the hooks came off.
I emptied the filter and took off all the pipes but when I used the machine again the pump was noisy.
I took the pipes off the pump but I cant figure out how to take the pump off, as it looks as if it is only pushed on to the plastic piping.I dont want to pull too hard on it as I might break it, can you advise me on how to take it off please.