Flow restrictor La Marzocco GB5S

We had some trouble on our La Marzocco GB5S with a lack of flow coming from our second group today here at Petrin Couchette in Marseille. Turns out to be a blocked/dirty restrictor which was easy enough to fix in the end!
Our problem was finding the restrictor because this newer model from 2021 is not like the old Linea PB!
So I decided to upload the video that I needed myself today! Hope this helps anyone out there