85 merc cruiser- impeller question

Think my impeller is not working correctly. Motor overheated last night, no water working threw engine then it staller. My question is how to take the motor apart to get to the impeller? can anyone help?

 

The impeller is in the lower unit. If the engine seized you have more serious problems. Impellers should be changed on a regular basis so you don't overheat and damage the engine.

 

Thanks gonzo, does the lower unit come off with just the two nuts holding it on and are ther any supprises i need to watch out for.like small pieces,rings washers ect....

 

Actually there are more. There is a nasty Allan screw that can only be reached after removal of the trim tab.

No parts will fall out, just two O-rings will stick to one of the surfaces.
There are several pump types, each with different impellers, so make sure you buy the right one.