1. Make certain you are using the email address associated with his WikiTree account.
2. Got to the Bulk Watchlist/Trusted List Changes page.
3. At the bottom of the page, select "Add to Trusted Lists" and click Continue.
4. Input his email address and click Continue.
5. On the following page near the top is an option to add him to the trusted lists of all his ancestors and siblings. Click the link and it will automatically select all the relevant profiles.
OR:
Select Laurenson-75 from the list and then at the end of the line for his profile listing select all descendants. This will then include all related profiles descended from him.
6. Scroll to the bottom of the page and click Continue.
This will add him to all ancestor profiles for Laurenson-223 at once or to Laurenson-75 and all descendant profiles at once.
You cannot add someone using their WikiTree ID, you must use the email address associated with their account. In the future, if there is a particular profile he wishes to be added to, he should go to that profile and make a trusted list request from the profile. It makes things a whole lot simpler.
Hope it helps.