Changing Juniper root authentication passwords and SNMP

Good day.

We are trying to change our passwords on our Juniper EX 4200s.

We have tried

edit

set system root-authentication plain-text-password

<new pass>

<new pass>

and then

delete snmp community <old String> authorization read-only

set snmp community <new String> authorization read-only

commit

But when we do this, it errors out on the verification of the new password.  It has been a while since I have done anything like this so any help would be greatly appreciated.  I believe the Cisco changes will be fairly easy.

We have Orion Core 2012.2.2, NCM 7.1.1, NPM 10.4.2, NTA 3.8.0, IVIM 1.5.

Thank you for your assistance.

Dwane