how do you pronounce.....

Ah, now I understand what you were saying about the r becoming a d!

The 'r' sound in Irish is different to how we pronounce it in English, well at least how native speakers of Irish pronounce the Irish r. The only way I can describe it is that when you roll your tongue back to pronounce the r in English, lift the tip of your rolled tongue higher towards your teeth so that there is less space for the air to pass through.

Experiment with the different sounds you make when your tongue lifts and falls in this position. The 'd' sound you are hearing is the lifting taking place as quickly as if it were a flicking of the tongue.

By the way, some native speakers don't bother with the special 'r' sound anymore, but well done for noticing it!