Hi Ben,
There is no formal procedure for renaming a survey as it involves multiple parts. There is survey Form item, the Feature service and the Folder. If you want to rename all 3 you can not do this easily without likely breaking something, but it is possible if you update all the itemIds in all the required files.
If you just want to change the title of the survey that the users see in the field app, web app or website, you can simple rename the Title in Connect and re-publish. But this does not change the Folder name and Feature service, or rename the xslx file and other files inside the Form item.
The best way once your survey is final and ready for production, is to create a new survey with the correct and final name, this will create the Folder, Feature Service and Form item all with the same name. To do this you can use your last test survey xlsx file, create a new survey based on existing file (bottom option when using create survey menu) and then give it the new name.
Regards,
Phil.