Hi there ,
There is no way for you to delete somebody eleses url unless that person allows or removes it from his/her website.
However, I have done this sort of thing several times with clients rip-off reports or a client where somebody posted a blogpost of her being an escort. The way around this is to knock off that page on 2nd page of google so that it won't get much visibility .. and that is done when you bring some more pages rank them above it .
So for this you need to create sevral free resources properties and then optimize those and rank them for the same keyword and knock the other website off the first page. This takes time and money. People could be commiting you that they can remove that , but you can't remove something from google index unless google allows you to do so or you get the person to remove it from there website/ blog .
So this would be atleast 2-3 months work , where we can spread this job into three monthly milestones ....
Regards,
- Syed