I have precompiled Android Kernel and modified it. After builduing I got an zImage. The Question is how can I install and boot the zImage on my raspberry pi 2?
I'm using a SD-card.
Unless the modifications you've made involve incorporating the tweaks that make the Raspberry Pi kernel what it is (I think this is more than simply "ARMv7"), this is doomed to fail, but it is simple enough to try.
First you need a card set up for the pi, the easiest way would be to just use a Raspbian or some other image, and then you can overwrite the root filesystem in the second partition as you see fit (with Android I guess, but again: this is certainly doomed to fail). The important part is the small first VFAT partition, which contains the bootloader code, etc., and the kernel. There will be a text file in there,
config.txt. Copy your kernel onto this partition, and add a line at the top of the
mykernel.img should be whatever you've named the kernel binary. You may also want to look at
cmdline.txt, which contains parameters passed to the kernel by the bootloader.
Lots of documentation, etc., on the official github page. Beware that people have already made various efforts to port Android to the pi and as far as I am aware none of them have been very successful.