My nostrils are crooked and my nose leans to one side now. What can be done to fix this? (photos)

Overall your nose has a nice shape, and revision rhinoplasty to realign the cartridges should correct the problem. However, revision rhinoplasty requires a more difficult dissection to  separate scar tissue from the original operation from the delicate cartilage framework.  The 5 cartilages that form the framework of the lower 2/3 nose have healed in an asymmetric fashion.  A precise dissection to mobilize the cartilages, and any cartilage grafts you have that were placed will allow them to be repositioned.   It is important to choose a surgeon experienced in revision rhinoplasty, and look at before and after pictures.

Every face naturally has some asymmetries, and even after a rhinoplasty, some asymmetry may occur during the healing phase. From the photos that you have provided, the collapse seen in your nostril and crookedness can be adjusted with a revision rhinoplasty. A cartilage graft can be used to provide additional support in your nostrils. Moving forward, I would recommend you to complete an in-office consultation with multiple board-certified plastic surgeons to complete an in-office assessment. This will allow them to assess your breathing and gain a better understanding of your goals

It's uncommon to perform a revision operation only to improve the symmetry of the nostrils. As much as they seem to bother you, they are not that an important part of the appearance of the nose.But you notice that your nose looks different, and worse, from one side compared to the other. That is often the result of asymmetry of other parts of the nose as well.Some of your views make your nose look still big-ish in some dimensions. For example, in some of the views, it looks as though the tip could be brought back closer to your face. And the tip could be elevated some. And in some views the tip looks wide, wide enough to address in a revision. For example, the photo #3 of 7 that you posted in your August 5 question makes the tip look rather prominent and wide.This matters because sometimes, we wouldn't do a big operation (and a revision is always big) to try only  to get nostril symmetry, but if there are a few other changes to be made, better nostril symmetry can result from those other changes. And making the nose smaller overall makes any remaining asymmetries smaller, and thus less bothersome.I'd love for you to see some excellent professionally-designed morphs of what could possibly be done with your nose. Morphs could also help you identify what's bothering you, and help you set a goal for the rhinoplasty that's accurate for your tastes. Profile and three-quarter views would be particularly important in morphing your nose. (Side note: in my opinion, morphs should always be done by the surgeon, or he should direct an assistant as she makes the morphs. Morphs should be made with a constant eye to what actually *can* be done in surgery, for that particular nose, and only the surgeon has that information and judgment. Another aside: I also recommend that you not show morphs made by one surgeon to a different surgeon. If a surgeon makes his *own* morphs, you get to see whether he understands the important issues of your nose, and how your nose should be changed. But if you show the surgeon someone else's morphs, and he says "Of course I can make your nose look like that," then you don't really know if he fully understands, or even recognizes, the important changes shown in those morphs. And you don't know if he can make those changes during surgery.)
Remember also that rhinoplasty is an exquisitely difficult operation to get right, and you should only have surgery if you are able to make yourself very confident in your surgeon's skills. The changes that your nose needs require advanced techniques, and skill that most plastic surgeons don't possess with expertise. For most noses, it's much better to not have surgery than to have inexpertly-performed surgery. Read my essay on how to stay out of trouble while selecting a rhinoplasty surgeon. And for those who have had previous surgery, it also discusses how to tell whether your first surgeon should be performing your revision. And it also discusses how to take photos that are best for online evaluations.
Your nose is also a perfect example of why computer imaging is mandatory in rhinoplasty. You need to know exactly what the surgeon is planning to accomplish -- what features he thinks he can change, and by how much he thinks he can change them. I always email morphs to my online rhinoplasty consultations. When you see the surgeon's goals in the morphs, you'll know whether he has an eye for an attractive nose, and whether he shares your opinion of what constitutes an attractive nose. You'll also know whether the changes he proposes are large enough to be meaningful to you, and whether he understands your wishes enough to address all of your priorities. How would you ever get that figured out without the morphs?

Revision septorhinoplasty for a straighter nose. Yes this can correct the problems you have described while giving you a better airway. See a very experienced revision rhinoplasty surgeon who can show you dozens of photos of revision noses like yours and worse with natural results.

Revision rhinoplasty is more difficult than a primary rhinoplasty, therefore a  in-person examination is going to be required to make a determination about how best to proceed. There are some minor improvements that probably could be made, but it's also important to know how much cartilage is left over in the inside of the nose for potential grafting purposes. There is no perfect nose, so it's imperative to have realistic expectations.