yamaha 40 hp outboard. spark plug wires

is it hard to change spark plug wires on a 40 hp motor. my second wire seems to be not firing. if not how do you go about it. can it be done without changing the coil.

[boats.net]

The spark plugs are made into coil and can not be replaced
, only the spark plug boot.

plug wires

so when i go to buy a part do they have just the boot that u can replace