Answer:
To the best of my knowledge (and I'm not a doctor, though I have some experience in the matter) the worst of it should be over in about two weeks (possibly four or five days), though I suppose that depends on how high of usage you have maintained and for how long. You should be more or less completely over the withdrawals in a month or so. It's not a fun experience though.
There's also the taper off approach but that really only helps if you have access to more hydrocodone (or any other opiate). However in most cases if you had access to more you wouldn't be in withdrawals in the first place.
If the above suggestions aren't an option then being miserable for a while until it does subside is your best bet.