If the maintenance manual does not provide rigging instructions, you could contact Tecnam for clarification of the procedure as it is something they should be able to provide. Sycamore's description is a good starting point, but the factory should be able to supply more detailed instructions. Something else I was thinking of: do you have a maintenance organisation nearby, preferably one with experience of dealing with Tecnam types? A friendly chat with someone there might also be useful for you.