Hi,
You'll have to make the changes from CLI. Please follow this link to instructions on how to configure multiple user accounts in WiNG. Also applies to NSIGHT.
https://extremeportal.force.com/ExtrArticleDetail?an=000082192
For password change: https://extremeportal.force.com/ExtrArticleDetail?an=000078696
You role for admins is superuser.
I hope this helps,
Chris
Christoph S.