To get the lastest version of CleverReach for Salesforce you have two possibilities:
If you already were using API Version 3 in CleverReach you don't have to do anything for it to work. Otherwise you need to do following configurational steps first.
Check that the scope looks like in the next step to verify.
You can delete the old OAuth as it's not needed anymore. Please don't close this Tab as you'll need it now in Salesforce.