The puke tube on my Liberty is sealed and buried out of reach within the body panels.
Today I replaced it with a longer, drainable tube from a KYMCO. Only had 4 scooters - but all others had a drainable puke tube - not this Piaggio. I could see oil in it - but couldn't drain it.

Remove lower front panel, then the underseat bucket. Remove the closest floor panel screw, and the screw holding front edge of red body panel.
Remove the left foot peg. and the two nearby panel screws.
All the above is to free up the lower panels to get your hand in there!

On a warm day raise the lower edge of the panels and reach in with hand & pliers and move the puke tube clamp down, then gently pull off the tube. I put the pliers through the foot peg space - with hand under the panels to pull off the tube.

Replace the tube with a longer one, slip new clamp back up on the tube.
This takes patience.

The shorty sealed Piaggio tube....buried.