I just rooted my Nexus 5 using this method: http://www.phonearena.com/news/How-to-root-Google-Nexus-5_id49014
I also enabled USB debugging in the developer options.<
This answer ended up working for me: https://stackoverflow.com/a/15559278/53001
Backup to a file, pull the backup, and then convert it to a tarball and extract it.
adb backup -f myAndroidBackup.ab com.corp.appName
dd if=myAndroidBackup.ab bs=1 skip=24 | python -c "import zlib,sys;sys.stdout.write(zlib.decompress(sys.stdin.read()))" | tar -xvf -