Hi Ray. If there is someone in your ancestral line showing an incorrect relationship, you can remove that relationship by opening the Edit window on your ancestor's profile, going to the 'Edit Family' section on the right side, clicking on the applicable [add/remove ...] link, and following the instructions from there. You can do that yourself if you're the Profile Manager or the profile is Open, otherwise you'll need to contact the other PM to get it done, or ask to be added to the trusted list.
In a case like this it's normally advisable and considerate to contact the other PM anyway, to compare notes and evaluate the sources each of you are using. One reason is that there is often more than this one connection affected, since each of the involved profiles has other connections as well. Another reason is that WikiTree is a single tree model, so it's not really "your" tree, and you can be changing the ancestral lines of a number of other descendants as well. As you probably know, that's also why you can't just delete a profile that turns out to have a wrong connection.
