I think you can successfully soften the scars with microneedling. The scars will never completely disappear but they will become less visible and much better in texture.
You can read here how microneedling works on scars:
https://http://owndoc.com/dermarolling/how-dermarolling-works/Stamp the scars every four weeks with the 1.5 mm dermastamp. You do not have to stamp all scars in one session. You can spread it out to several sessions but stamp thoroughly. At your first session, do not stamp densely, do just a small part of a scar and do it lightly to see how the skin heals. It may stay red for a long time but that is OK.
Yes, roll the scars twice a week with your 0.5 mm dermaroller.
You should also use 0.1% Tretinoin cream and apply it on your scars right after stamping. Wait about five minutes and apply a little Infadolan on top of the Tretinoin.
Apply Tretinoin to your scars also without stamping. Apply it every second or third day. Initially, it will make the skin red and dry so moisturize it with either Infadolan or some oil.
Tretinoin helps but it has to be used long-term and it can make the skin red and a bit irritated so do not give up - continue. You can reduce the frequency of application if the skin gets too irritated.
You can apply Tretinoin after rolling with the 0.5 mm but dermarolling greatly enhances absorption of skin products so it may make Tretinoin too irritating. If it does, apply it on the days when you do not roll.
Do not use Tretinoin if pregnant, planning the pregnancy or breastfeeding.
If some of your scars are raised, do the pressure massage on them after stamping but do not do the pressure massage if the scars are not raised. The massage is described here:
https://http://forums.owndoc.com/dermarolling-microneedling/what-to-do-about-hypertrophic-scars/Please let us know how things are going for you after about four months.