Hey there, atuum!
I'm truly sorry to hear about your WD My Passport.
The fall most probably damaged some of the internal components on the HDD and judging by the clicking noise, it's most probably the platter.
I'd definitely NOT open the enclosure of the WD My Passport Ultra. The My Passport series are hardware encrypted, which means that if you take it out of the enclosure, it will make the data on the drive impossible to recover and you won't be able to access the drive without a professional help.
I'd recommend contacting our tech support for further assistance on how to proceed with this.
Contacts:
http://goo.gl/X38b7C
Hope this helps you! Good luck!
SuperSoph_WD