If you already have a Map Reporter account, you can use that to report problems you find on HERE Maps (http://mapreporter.navteq.com/). If you don't have a Map Reporter account, you can use HERE Map Creator on here.com.
HERE Map Creator lets you add streets and roads in more than 100 countries. You can also change the map and make corrections if you find something wrong.
If it's not possible to make changes in your country using HERE Map Creator, first go to the place on the map where you want to report the problem. Then right-click and choose Report map changes from the menu. Finally, choose the type of problem or change you'd like to make, giving as much detail as you can.