How to change a Solaris zone netmask?

So it's all in /etc/zones/.xml but they tell you not to touch it.

In here:
http://forums.sun.com/thread.jspa?threadID=5075758

They tell you to run this:

zonecfg -z email-zone
zonecfg:email-zone> remove net address=10.1.30.232
zonecfg:email-zone> add net
zonecfg:email-zone:net> set address=10.1.70.232/24
zonecfg:email-zone:net> set physical=bge0
zonecfg:email-zone:net> end
zonecfg:email-zone> commit
zonecfg:email-zone> exit

Use this format for new-ip to configure a specific subnet mask: 10.1.30.232/24.