Hi
I went up and had a look this morning, and it's not something I'm equipped to help with. It's certainly well in and stuck, but guys with the right gear will get it out no problem
It will need a winch and perhaps another motor to anchor it as the grass surface is very wet and slippy. If they stay far enough out the ground is solid enough to take the recovery motor, but being as wet as it is, it won't take much action before the ground starts to churn up
The problem is that it's bottomed out and the wheels have dug themselves in and created a wall in front of them. I don't think going in from behind would be realistic for the recovery motor and suggest digging a small slope out in front of the front wheels and pulling from the front.
Sorry couldn't help