I dont think there is a pin for the pump on a tdci.
i normaly just take the covers off
take the rocker cover off
put the flat plate in the back of the cam
put a tipex mark on the pump
loosen the bolt on the cam pully but dont take it all the way out
give it a gentle tap with a hammer to free it off
then loosen the tensioner and take the belt off

Fit the new belt and tensioner
tension the belt then tighten the cam pully bolt
turn it over by hand a few times and make sure its all timed up
then covers on