It's always difficult to say that X change will lead to Y points. The points depend on the scoring model as well as the rest of one's credit in addition to the change. If you're removing all derogs then you will probably see a fairly signficant improvement. That's why we always recommend addressing derogs first. They tend to have the biggest impact and hold one's scores down as long as they are on reports.
If you still have derogs after this then the improvement will probably not be as significant.
