How do I overwrite the old version of CC Cleaner

How do I overwrite the old version of CC Cleaner

You don't. CCleaner is supposed to clean all old files when you install a new version. Not a single old file will be left behind.

So just download the new version and install it. :)

If you have any issues let us know.

As Fireryone says, just download the new version and it will automagically install over the old one :)