Auto Shapes in Microsoft Word Organisation Charts

[HeyJude]

Hello, I have searched this site for answer to this question but had no luck, if I have missed it apologies in advance.

 

My question is how do you ungroup and change the sizes of individual shapes or text boxes in word organisation charts which have been inserted via "insert diagram". I can resize or move the whole chart but there does not seem to be an option for ungrouping or resizing. Do you know how?

 

Thanks