ReLine or slip line but with traps etc it depends on the situation. Tearing up walks, beds etc is also a pain. As someone else stated if the line is intact and not broken cut the roots out clean and then treat as needed with the root killer stuff. The joints on those clay pipes are notorius for small feeder roots to find there way in. I have an old place in the country with this issue and it works for me. Of course every situation is different.
Depending on where the problem is u can also replace a bad section with the collars that fit the clay/concrete to PVC sections that work well.