Changing the Raw Water Pump Impeller?

[johnmurray]

My A30 FC has the Yanmar 6LPA engine. The servicing guidelines recommend changing the impeller in the raw water pump every 300 engine hours. I use a professional to service my boat and at 900 hours he has just completed his third impeller change. He finds it unusually difficult and time-consuming to do this task because of the very awkward access point in the quarter berth and the positions of all the bits and pieces that surround the pump. He considered removing the pump completely and doing the impeller change on the bench but he found that removing the whole pump was even more difficult than removing the impeller alone. (By the way, in each 300 hour change the old impeller looked just as good as the new one still in the Yanmar package.)
Has anyone any suggestions as the best way to do an impeller change?

[Carl]

On my flush deck i change it every other season by pulling the pump as PM. Cant imagine trying to deal with it while adrift. Keep an eye on the shaft seal, when it starts leaking it flings raw water on the side of your motor. Things always look new until they break