There is good advice here.
https://www.drinkdriving.org/drink_driving_information_earlydrivinglicence.php
However, the fact you HAVE been promoted at work will go against you. Most people apply for their licence back to get a promotion that wouldn't be possible unless they have a licence. As you are, presumably, already doing your new job without a driving licence you need to ask what reason the court would have to give you your licence beyond convenience.
Courts do not normally give back licences simply as a reward for a promotion.
Secondly, you need to think what evidence you can provide that you have changed and if the same circumstances occur you wouldn't make the same choice. Most DDs happen because the person is dependent on or misusing alcohol. If that is the case promptly going to your GP, attending an alcohol awareness course or regularly going to AA meetings, with appropriate documentary evidence, can be strongly favourable.
If it was a one off thing you need to be more creative. Try not to just say it was a one off mistake because the magistrates view will almost certainly be that almost all drivers don't decide to drink drive whilst considerably over the limit. There is always something you can do to stop yourself being in the same position again.
That's not to be negative, but you will get a grilling from the magistrates or judge so you might as well plan in advance.
Beyond that it's the same for most court cases. Dress smartly. Be polite and deferential to the bench. Be careful not to say anything that sounds like an excuse for or playing down the seriousness of the offence. Try to focus on the benefit the promotion will have on those around you rather than yourself. If in doubt say you are ashamed you placed other road users at risk, ashamed you have wasted the time of the court and apologise.
You will have the strongest case if you can demonstrate that you have made concrete steps to move on from the offence and that your driving licence is essential for you to continue those steps.
