issue with running both 2.5 and previous version side by side?

I loaded Traktor Pro 2.5 and although I want to use it - I am not ready to gig with it.
I want to revert to the previous version for when I do play out.
I was told that there is a backup file in applications where I can run the previous version.
I am on a mac-
Application-native Instruments, traktor 2-?
There is no file called Backup?
I did a search and found no file with this previous version.
So now I just have 2.5

Can I re-install previous version while 2.5 is already on my drive?
OR
Do I need to uninstall all NI Traktor software and start completely from scratch? *if so what is best method....

I have no idea what is going on with this so any help would be appreciated!