Safely delete all visits from a provider

For the past 6 months or so, I didn’t realize it but all my results are skewed due to a spam bot scanning my site. Most all of the bots are on the XLHOST provider. How can I safely remove all the visits from them? I would prefer a one time thing (not a segmentation or anything). I have blocked all of the IP address subnets from connecting to my server.

Thanks!

I accomplished this by manipulating the SQL query on github…