There is unfortunately nothing in the Ford WSM on how to exactly perform this procedure or anything linked directly to this procedure.

The only thing IIRC is to remove the spark plugs and then inserting the Boroscope inside the spark plug wells ,then pressurizing the injectors by turning the key on,while at the same time looking for a drip into the cylinder,side note do
not crank the engine while Boroscope is inside the cylinder.
The other option is to have it Diagnosed with IDS Software to perform an injector Flow Test.
Hopefully LMS or others will have a broader perspective on exact detailed instructions. Z