You can access the survey by logging to win.ihg.com website and by scrolling to the Survey-icon.
You will then be asked few screens of questions about hotel stays etc.
When I tried to submit the survey, I am not sure if it was successful. I think that I saw briefly something that indicated so, but the survey completion window didn’t render properly. I could go back and do the survey again?
EDIT: The 100 survey points immediately posted to my account. You can check check this by just logging to your IHG Rewards Club account and having a look at your recent transactions.
If you do the survey now, try to get a screenshot that you have actually done it. There seems to be something wrong with IHG’s website and I am not sure if these survey responses are processed correctly