Hi, I got married with my friend in vegas 8 years ago , we still friend but no longer together, we would like to cancel it but we don't know how to

The details and history are a bit sketchy, and there is no simple way to "cancel" an 8-year-old marriage, but we have done many annulments for foreign citizens.  With some information about the cooperation of the parties, and some basic background facts, it woiuld be possible to tell you (usually) how long it is likely to take, relative odds of success, and how much it is likely to cost.  The background needed is explained on two pages of our web site:http://willicklawgroup.com/annulment/. http://willicklawgroup.com/uncontested-annulment/.If, as you indicate, the marriage was in Nevada, no physical appearance, and no establishment of Nevada residency, should be required for an annulment proceeding (i.e., neither party should have to come back to or be here).  Citizenship is not relevant; the question is the satisfaction of statutory grounds.  If that is not possible, then the only alternative would be divorce, presumably where one or both parties now lives.