How is this done plase?
Copy the ini to another location (like desktop, or external disk)
Uninstall ccleaner
Reinstall
Cut the ini from the desktop and paste it in the new ccleaner folder
You can just reinstall CCleaner without uninstalling the old one first. If you do it that way then it keeps the existing .ini; and also keeps your licence key if you have Pro.
It's someting that I do quite often. You can download an installer from the builds page: https://www.ccleaner.com/ccleaner/builds
Note that if you do uninstall/reinstall then Windiws may tell you that you do not have permission to paste the old .ini back into the CCleaner folder.
if it does that then use CCleaner to save a new .ini and then overwite it with the old one that you had saved.
If it still won't let you do that then edit the new ini, overwrite the contents by pasting the contents from the old one over them, and then save it.