Scooter / Bike driving licence (Athens)

Hi all,
Does anyone know how I would go about taking motorbike lessons and obtain a driving licence for motorcycle?
I'm tempted to just go to a 'driving' school and ask, but I'm very limited with my Greek.
I already have a European car drivers licence, but never been on a bike and would like to learn and get the permit.
I live in the northern suburbs (Maroussi), but willing to travel if you can recommend any schools that cater for non-Greeks / English speakers.

Ta

Michel