There is a much simpler way of doing this, and it's the way I use. Simply download the Ubuntu Mainline Kernel Updater script and run it from a terminal. It will download the .deb's for you, install the new kernel, and optionally remove the old one (not recommended) then optionally reboot.
Example output (copied from my terminal):
evilsupahfly@the-black-beast:~$ sudo KernelUpdateChecker -no-rc -r utopic
Run this command to install the new kernel
Rejecting Release Candidates
Accepting Latest Kernel
Accepting kernels compiled for utopic
Accepting kernels with a version higher than 3.15.0-031500-lowlatency
2014/06/16 @ 18:41 (YYYY/MM/DD @ HH:MM)
Care to look at the change log? (y=Yes, n=No) (n)
(download output skipped)
I (the-black-beast) am now self aware and a sentient being, have a nice day.
Oh and by the way SKYNET is now active.
Installing Linux 3.15.1-031501:
(installer output skipped)
The New Kernel looks to have been installed
WARNING: If the new kernel does not boot you may regret saying yes here.
Would you like to remove the current one? (y=Yes, n=No) (n): n
Are you ready to Reboot? (y=Yes, n=No) (n): n
Almost entirely automated, and completely problem free.