If you get fresh kalamari, which we usually do in Greece, you will have to clean it first. Frozen kalamari are usually cleaned.
To clean the kalamari, remove the part where the head and the tentacles are and cut head off and keep just the tentacles making sure not to break the ink sac and then remove the white small ball in between them. Then remove the cuttlebone from inside the Kalamari and remove everything inside the sac and wash well.
The body of the kalamari has two fins. If you are going to stuff the kalamari, you can either leave them on or use them together with the tentacles in the filling.
For frying cut the body into 2 cm rings.
Other relevant posts:
Kalamaria Tiganita (fried) and Gemista (stuffed)