Hi,
Sorry for the insistence, but it does seem from the pictures that you have "red bumps" that could be construed as active acne; redness is usually a sign of on-going inflammation, and acne can be there without ever "blowing up"; I myself had some pretty nasty raised red bumps that were just painful and never "came to a head" and lasted for a very long time, which can be a sign of cystic acne. It also is pretty much counterproductive to treat scarring while there is active acne.
So, taking you at your word that it isn't active acne (but really the pictures do seem a bit confusing in that regard), I think it goes without saying that if you can, you should be seeing a dermatologist, specially because acne scaring (you have truly scaring, and not only pigmentation) is something best treated by medical professionals; there is little to be done at home. That said, it doesn't mean you can't make it better with topicals: others have mentioned glycolic acid, and any AHA would be a good choice (lactic, mandelic, malic, etc, whichever works better for you) or PHA (gluconolactone, etc) as well, since those kind of acids are gentler when used correctly and resurface the outermost layer of the epidermis, and through that action also stimulate the dermis. Retinoids might also help. None of those topicals will be able to completely solve scarring however, and even their best result might not be what you would find acceptable.
I don't know much about dermarolling, but I believe it is a recognized treatment for scarring (and there aren't many treatments for scarring that work!). I would check out http://barefacedtruth.com/, a blog of a couple of doctors (which have their own product, but never mind that), because they have written a couple of really good, science based articles on dermarolling or micro-needling. Like others have mentioned, it is very important to do it correctly: that means preparing skin, actually dermarolling, and treating skin correctly afterwards as well, using the right products, etc.
I think it is important to keep in mind that scarring is a inflammatory response; some are more prone to it (and cystic acne is know for having a higher risk of scarring), but it is nevertheless an inflammatory response that any one of us could experience; to say it in other words, it is a natural process of life gone amok; basically your body is trying to deal with that damage by producing the wrong kind of tissue, because inflammation has gone on for too long or too strongly. I say all that to try to point you to the complex process involved both in the formation of scarring tissue, and on its reversal. Being an inflammatory condition, you should take measures to reduce inflammation, both in the body as a whole (by eating right, exercising, relieving stress, basically a healthy lifestyle; I know it's almost impossible!), and also specifically in your skin: you need to pay attention to skincare (cleansing, moisturising, sunscreen, antioxidants, etc). Now, and again, none of that will undo scarring on its own; but even when you find a medical professional, and perhaps try micro-needling correctly, or perhaps lasers (which don't work very well for scaring, depending on your specific type of scarring; that's for a doctor to find out) or medical grade resurfacing peels (which also aren't very promising, also depending on type of scarring, time of damage, etc), all that needs to have a non-inflammatory environment to be able to heal correctly (that is, producing the right kind of tissues and not the wrong ones, which lead to scarring, yet again). It should also be noted that no one treatment will be able to resolve scarring, we are talking about a series of treatments spaced out through several months.
So, to summ it up: definitely look up exfoliating acids (vinegar, AHAs, PHAs) for home use, they can help but not solve the problem. If at all possible, try to rethink your lifestyle and food choices, as well as your skincare as a whole; this can't undo damage but can set you on a path of controlling inflammation. If at all possible, and for the best chance to solve your scarring, try to see a medical professional, a dermatologist or plastic surgeon, and talk to them about your options.
If there is active acne, and specially cystic acne, you need to get that under control.
Sorry I can't be of more help.
Best,
Lucas.