@asle . Concerning the speaker,all you have to do is to use a thin nozzle to spread the silicone around the old speaker's sticker(the nylon sticker is usually found glued to the screen)hope you noticed it.you can also use a medical syringe to dispense the silicone on it.Be very careful not to mess it with extra silicone.I did not do ant pressure test because I was very sure that my xperia z3 is waterproof again.I used it in water several times and still working.Note:this is my second time replacing the screen.
Good Luck