In the Settings option of Nelio Content you can delete a social profile from Nelio Content. Doing so, nobody can schedule new social messages nor any scheduled message will be published. However, Nelio Content will still have access to that network, since you can have other websites that do have configured that profile and thus need to post messages on it.
To completely delete Nelio Content permissions on LinkedIn go to your LinkedIn account (in LinkedIn’s website) and select Privacy & Settings (under your picture menu). In this new window, there is the Third Parties tab showing the list of third parties that that have access to your account. Click Third party apps and the list of apps that is shown.
Finally, click on the Remove button shown at the right of Nelio Content and the permissions will be revoked. Of course, you can always return to give Nelio Content permission to access LinkedIn.