Hi Guys , looking for some advise please

Yesterday whilst the car was on the rolling road getting set up, the heater matrix decided to let go, we managed to by pass the pipework to continue with the setting up of the car

It was only on the rollers for no more than 10 minutes when it went , and it looks like its just wear and tear that caused it, car was Ok the rest of the hour on the rollers

Who has changed one before , and how difficult is it, on past experiences with Mk4 escorts theyre a pain in the RS

Is there maybe a technique to get the thing out , any help or advise would be much appreciated