Access to raw water impellar on IP 370

I have, new to me, a 2004 IP370 with the Yanmar 4JH3E engine. I went to inspect and change the impellar and saw the access appears to be very difficult due to the location of the pump facing aft below the alternator. Is there any easy way to to access this pump without the removal of various parts? Thanks for any help.

Looking at a picture of the 4JH3E it looks like you have slightly better access than the 3JH2E on my 97 IP 37.
A few weeks ago, I had to drop the starter motor to get real access. I subsequently found out Yanmar makes an Impeller Puller (129671-92110) and newer threaded impeller (129670-42610) - see picture.
Maybe check with the Yanmar supplier if the parts are the same (or they have similar) for the 4JH3E motor for the next time you have to replace an impeller.
Mac

Thanks Mac, I'll get the puller. Any 370 owners around that can tell me how they access the water pump?

I own 370-24 with the 4JH-3 engine. I lay a foam pad on top of the engine( pulling back the water heater hoses out of the way) and there is room to access the cover. Can also be done from the aft cabin. Dealing with the screws on the cover was a pain as they are slotted head and do not want to come out.  I added many years ago the Speed Seal cover  with the large thumb screws to make ti easier to remove the cover - this product may not be available now however. At that point I used the smaller of the two Jabsco pullers (it will fit in there) and pulled out the old one after some cursing.  This was not easy but got done - if using screws, get some extra screws as they fall into the engine pan and you can fish them out later. 

When Yanmar came out with their little impeller puller tool matching the new impellers with the threads in them as reported by Mac,  I switched to use them. Old impeller comes right out. This is much easier than using the Jabsco puller. I have not had to remove anything. Use non-petroleum lubes such as glycerin on the new impeller.

Thanks for the reply.