how to remove negative reviews

did you tried to solve it? if under the bad review there will be another answer that the issue is fixed and they write positive one this will be double positive as you are solving your customers issue, means even if this happen again people who read the review will be confidence that you are going to solve it anyway so..

I'm from germany an already made a delisting from google. It's possible in EU. You have to upload ID and declare why it's wrong, outdated etc.
Search Result will never show up anymore, but review is still there whe searching via bing or yandex.

Another tip would be to give the domain owner money for removal.