1995 5HP-2 Stroke, Clogged water cooling line

[Jeffatoms]

I just disassembled my lower unit and replaced the impeller, reassembled, started it up and no water ran out the pee holes. The old impeller was missing all vanes and I only recovered two in the water pump housing. I am going to take a wild guess and predict that the remaining impeller vanes are up in the water cooling line leading up to the power head. How do I get them out without disassembling the entire powerhead? My first idea was to blow compressed air through the two pee holes half way down the shaft.

[boats.net]

The cylinder head and engine on that engine comes off easy, probably best to remove and clean.