minor: clarification of replica set procedure

Author: Sam Kleinman

source/tutorial/convert-standalone-to-replica-set.txt

@@ -60,7 +60,7 @@ installed. If you have not already installed MongoDB, see the
    status of the replica set, use :method:`rs.status()`.
 
 #. Now add additional replica set members. On two distinct systems,
-   start two new :program:`mongod` instances, as above. Then, in the
+   start two new standalone :program:`mongod` instances. Then, in the
    :program:`mongo` shell instance connected to the first
    :program:`mongod` instance, issue a command in the following form: