When you check-in a beer and have enabled geolocation, your checkins are geotagged, just like your photos are Geotagged with Instagram. This gives the ability to add a location to an existing check-in that you may have forgot or simply want to remove.
Please note that if you don't check-in your beer in the place where you want to add your location, you won't be able to add it later. You must be physical near the venue to add it. In addition, you only get badges for checking in, so adding a location post-checkin, will count for badge, but not grant it until you check-in.
1. To do this, navigate to the check-in where you want to add or remove the location, and select the pencil icon in the upper right corner.
2. Select "Edit Check-in"
3. Add your location using the "Location" feature
4. Select Save once you're done and your check-in will update!
*Please note that only venues around you at the time of the check-in will count. Checkins that are done via the web, or third-party applications are not geo-tagged and will not be able to have locations added.*