Update: you will likely prefer the newer version for Raspbian Buster.
Here’s how to use the KeDei 3.5″ touchscreen V2 with your own kernel.
I recently bought a KeDei 3.5″ touchscreen V2 for my Raspberry Pi 2, but do not want to use the old kernel and untrusted images provided by the vendor. However, the display needs a customized kernel and drivers to work. To make it work on a vanilla Raspbian Jessie, the fastest way is to use my precompiled kernel and otherwise follow Heikki Virekunnas’ TL;DR.
To recreate the package or automate the install directly to your Raspbian (not NOOBS) SD card, you can use my script.