how to I restore a shape to a master?

[sara]

I have edited master shapes and now what to go through an existing
document and restore shapes created in it using the new master styles.

How do I do this?

 

[Philippe C.]

With a little 29 $ utility from Visimation. I haven't tried it yet, but I
only had a quick look at my trial version and it seems it will do the job.

 

[Paul Herber]

I have edited master shapes and now what to go through an existing
document and restore shapes created in it using the new master styles.

How do I do this?

If I read your question correctly you want to substitute one or more
shape for another. We have a utility to do this

http://www.visio-utilities.sandrila.co.uk/

There is a shape substitute that will do this for you.