changing UA#

I want to change the UA# for my analytics tracking – how do I do this?

Logged into website, tried re-authenticate with your google account, made sure I logged into the correct google account with the new UA#, pasted the google code from that account and saved the code, saved the record.

Then I get
Analytics profile – blank
Re-athenticate with your Google Account

There was no message to tell me what next, it looks like absolutely nothing has happened.

Same result if I uninstall the plugin and re-installed, slightly different message – Authenticate with your google account, but once data is entered and saved just a blank screen asking me to re-authenticate.

https://www.ads-software.com/plugins/google-analytics-for-wordpress/