You don't. Because there are no forms in either the Design master or the
Replicas. Or at least, there shouldn't be: it is a certain way to bloat and
corrupt the files (or 'blobs', as they have recently been described).
All forms, macros etc should be in an unreplicated front-end, and linked to
the (replicated) back-end.
You simply issue users with a new front-end as and when you have made design
changes to forms etc.