Help with flattening a part.

Hello. I need some help flattening this part. I've tried a number of ways and have had a good search round this, and other forums, but haven't found anything successful. I think my stumbling block is the fact it's curved in 2 directions.

I'm asking because i require a flat pattern for 3 axis cutting.

Cheers.

N

SolidworksParts And Features