Never done it before, but I would take a "copy" of the DB off-line on an R6 client.
Then I would replace the design (File, Database, Replace Design) using the R6 mail template.
Opn the DB in R6 and check it out? Since you're going to use a "copy", no harm will be done. If it works, be careful when applying it back to the server since the ReplicaID will be different.
Rgds,
John