Log in as Siteadmin and click on the Site Settings > Site Import Settings.
Click the next button at the timezone settings.
Now click on the Add Exclusion or Inclusion button.
From here you may select which type of Exclusion you would like to add; Folder, File, IP Address, etc. Then type the Folder/File/IP address you wish to exclude in the text box and click save then click next.
If you wish to reprocess your statistics to reflect the IP exclusion then choose the option to reprocess and click next.
Lastly click save and your site stats should begin to reprocess if you have chosen to do so.