Here are a few photos of the plug.

First is position to show how tight it is to get your one hand in.

https://www.dropbox.com/s/ysgn85b45c...15.33.jpg?dl=0

Second is a close up of the plug itself. Cant see any tabs.

https://www.dropbox.com/s/691816e9e4...13.15.jpg?dl=0

Third is a photo of the little wire at front leading to the magnetic clutch.

https://www.dropbox.com/s/qfg7ilgk58...39.27.jpg?dl=0

Fourth is an image of a compressor.

http://static.schmiedmann.dk/Product..._93005_big.jpg

You can see the sheath the plug is going into.

I have tried pulling on it but it does not just come out and only having access with one hand makes it very hard.

Any ideas? Inside there is only one wire so the connection maybe a flat metal pin or a round metal pin. Seems to held in place into those slots on the sheath.