Dispensation... and writing a letter to the Bishop

Hi everyone, I’m new to the site. I hope this is posted in the right section. I did a search, and couldnt seem to find the answer to my question. I’m in the process of requesting a dispensation (I’m catholic, but I need a dispensation letter because my fiance is Orthodox Christian). Anyways, I met with my priest yesterday and he said I need to write our bishop a letter, requesting a dispensation. The question I have is, how do I address him? (i.e Bishop Smith, or Your Excelency?) thanks…

There are several ways and here’s 4 or them:

Your Excellency (formal);
**Most Reverend Sir; **
The Most Reverend (his name); or simply
Dear Bishop (his name).

Good luck & many blessings,