Hello!
I have a couple questions for you. Are you using home (which is based off your Google Maps/Google Now)? Or a dropped pin to detect location? These settings can be found under settings > Security > Smart Lock > Trusted places.
You can tap on a dropped pin and remove it and try pinning again. But, if it's using "Home" that's a different story. You should be able to tap on "home" even though its greyed out and go to an edit page. You can delete the location from here and start fresh. However, keep in mind you'll have to re enter your home information into your Google services if you go this route. If you can expand a little on what you are seeing i'll try and help a little further!
Thanks!