Opening a New Account with Existing Retained Earnings

[Roger]

I have asked similar questions before but have yet to get an answer that 
I understand, so I tried just starting an account from scratch.  I am 
using 2.3.7 and started by setting up a new account assuming that I have 
Retained Earnings from previous years.

So, I thought what I wanted to do was simply put an Opening Balance for 
Retained Earnings in the Setup New Account wizard but it is grayed out 
not allowing me to make any entry.

What is the detailed (step-by-step) recommended procedure to get Gnucash 
to set an opening balance for Retained Earnings?

Thanks,
  Roger