There are three possible scenarios you may encounter while checking entries off of this list.
The Wikipedia article exists and the EWL article may both be on the same person already. No further action is required, just change the {{notdone}} tag to {{checked2}} and move onto the next record. If you wish, add an external link in the format:
The Wikipedia article exists, but is on a different topic to the EWL article. If Wikipedia does have an article on that person, change the Wikipedia link to point at the correct article. If Wikipedia does not have an article on that person, change the article title to an alternative, unused title. Then mark the record as checked by changing the {{notdone}} tag to {{checked2}} and move onto the next record.
The Wikipedia article title may be red, indicating that it does not exist. Check to see if we have an article on that topic, if we do, change the Wikipedia link to point at the correct article. If we don't, then leave the article title as-is, and set the record as being checked as above.
If there are any dubious or difficult records, and you are not sure what to do, change {{notdone}} to {{deferred}} to indicate that the entry is problematic, and move onto the next one.