Q: OS X Yosemite download failure, unable to delete corrupt version

bcht22, 

Thank you for visiting Apple Support Communities.  

Try deleting Yosemite from Launchpad and download Yosemite again.  I have included two articles that cover this process.  

Mac Apps

1. Click the Launchpad in the Dock.
2. Click and hold the app you want to delete.
3. The apps will begin to jiggle.
4. Click the X that appears.

If you change your mind after deleting a Mac app, you can download the app again if it's still available in the Mac app store.

How to delete content you've downloaded from the iTunes Store, App Store, iBooks Store, or Mac App Store

http://support.apple.com/kb/HT5772

Download past purchases

http://support.apple.com/kb/ht2519

Cheers, 

Jason H.