This is called "unlinking". You unlink a citation to one fact at a time. At either the Person Tab of the People page, or the Source Page:
1) Select the appropriate citation link to a fact
2) Look up in the button bar. You will see an icon that kind of resembles a broken chain link. That icon is for "unlinking" a citation to a fact. Click on that icon.
Repeat for each fact that citation is linked to for that person.
1) Select the appropriate citation link to a fact
2) Look up in the button bar. You will see an icon that kind of resembles a broken chain link. That icon is for "unlinking" a citation to a fact. Click on that icon.
Repeat for each fact that citation is linked to for that person.