Hi Rui,
Once the rubber cover is removed the textured part twists off anticlockwise. Ive attached a photo to show. Can be really stiff if they havent been removed in a while.
Cheers, Dan
There will be a d16 out there that will simply plug in I'm sure of that. Have a look at the shock tower and the plugs there.
Id would be surprised if d16w4 from mb MC civic doesn't just plug in. But I've never had one of those cars or looked into it.