This short walkthrough describes how to install the Ubuntu linux kernel 3.15 on without compiling.

This guide should work with the latest version of Ubuntu Linux and most Ubuntu-based distributions including Mint. The included kernel files have been compiled using the generic Ubuntu configuration.

Installation Guide (GUI)

1. Download the kernel headers package:
   
   http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-utopic/linux-headers-3.15.0-031500_3.15.0-031500.201406081435_all.deb
2. And the appropriate package for your system
   • AMD64:
     
     http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-utopic/linux-headers-3.15.0-031500-generic_3.15.0-031500.201406081435_amd64.deb
   • I386:
     
     http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-utopic/linux-headers-3.15.0-031500-generic_3.15.0-031500.201406081435_i386.deb
3. And the accompanying compiled kernel image
   • AMD64:
     
     http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-utopic/linux-image-3.15.0-031500-generic_3.15.0-031500.201406081435_amd64.deb
   • I386:
     
     http://kernel.ubuntu.com/~kernel-ppa/mainline/v3.15-utopic/linux-image-3.15.0-031500-generic_3.15.0-031500.201406081435_i386.deb
4. Install the files in the same order as downloaded above. So first install the headers (2 files) and finally the image (1 file).
5. In the terminal run:
   
   sudo update-grub
6. Reboot and select the kernel from the bootloader menu

I will post the latest version of the 3.15 branch and 3.16 release candidates in comments below.