I've not had to do this before but there are a few options available to you by the looks of things.
Use an query against the Mongo DB API similar to this:
//Connecting to the Analytics DB var driver = Sitecore.Analytics.Data.DataAccess.MongoDb.MongoDbDriver.FromConnectionString("analytics");
//Building our query var builder = new QueryBuilder(); var filter = builder.And(builder.GTE(_ => _.StartDateTime, DateTime.Now.AddDays(-30)), builder.EQ(_ => _.SiteName, siteName.ToLower())); //Retrieving data from the "Interactions" collection var interactions = driver.Interactions.FindAs(filter)
http://sitecorepro.blogspot.co.uk/2015/06/starting-with-sitecore-analytics.html or http://www.nttdatasitecore.com/Blog/2016/July/Retrieving-Interactions-Data-from-MongoDB-using-Sitecore-Analytics-API
- Use Sitecore Experience Extractor :https://github.com/Sitecore/experience-extractor