Well, I wouldn't be looking to Ronnie for the perfect pronunciation of Irish! (I can afford to say that, being a fellow Dub). A rough phonetic representation would be:

fawg-him-eed-shood-mor-a-taw-shay
- with stresses on the first, fourth and seventh syllables. The o in mor is short

The literal translation is "We'll leave that as it is!". A better representation of the sense is the English expression: " 'nuff said!"

Regards