tracking user_ID

[#1]

I am trying to implement user_ID tracking in analytics under the ".js" feature. Sorry I am no programmer. Can someone help with assigning a "unique, persistent, and non-personally identifiable string ID" to an existing authorised user of my google site.

1. how and where do i assign this string to the authorised user's email address? can i do it simply through 'custom definitions'? what would the script be for such a definition?

e.g. 

user1: email1@email1.com - USER_ID: 00001

user2: email2@email2.com - USER_ID: 00002

2. would the tracker then look like this?:

ga('create', 'UA-XXXX-Y', { 'userId': '00001' });

ga('create', 'UA-XXXX-Y', { 'userId': '00002' });
ga('send', 'pageview');

3. what would the updated tracking code look like and how do i then upload it onto the google servers? Could I do it through the analytics site again, like 'customs definitions' without php implementation.?

Many thanks in advance

[#2]

You should to understand documantation wroted here or can ask questions about it.
https://developers.google.com/analytics/devguides/collection/analyticsjs/user-id

1. You can use email as userid.
2. No, you can use userid of a logined person - only 1 userid can be at one time.
3. To place your user to tracking code you need to know programming by the way.

[#3]

Thank you Darts,
I understand that if one used the email as USER_ID, it would be a violation of terms and conditions.
So how and where do i assign a USRR_ID unique string to the email, then please? Can one use "custom definitions" and how? Thank you

[#4]

Custom definitions is only tool to use your code data in Analytics, it cann't be used to create your data. So, only in your website code you can place your data to Analytics.