festive greetings to all!.
I've sprung a coolant leak 

, unsure of part number. It's the pipe that goes from the expansion tank to the water pump? The pipe has got a split where it's gone across the alternator belt ( alternator has been off due replacement of the voltage regulator) so the belt does need replacing now due to the leak! 
I think it's this part 
 
Is it easy to replace? 
It's for a 1.9 DG
TIA