How to install custom kernel from source? - Galaxy Tab 2 10.1 (GT-P5113)
I assume you're on Linux.

If the zImage already has a ramdisk in it (check by using unmkbootimg and confirming if you get initramfs.cpio.gz after decompiling), rename it to boot.img and do this in a terminal (Odin way):

tar -H ustar -c boot.img &gt; boot.tar


Or you can look for an existing kernel for your device, download the flashable ZIP for it, replace the boot.img inside with yours, then flash in CWM.