Here are the files that you need:
http://www.reverendkyle.com/download…arm-signed.zip
http://www.reverendkyle.com/download…DB_Drivers.zip
Be sure to install ADB on your computer first!
http://www.reverendkyle.com/index.ph…oid-in-windows
The commands:
adb shell
rm -r /data/local/tmp
ln -s /data/ /data/local/tmp
exitadb reboot
adb shell
echo ‘ro.kernel.qemu=1′ > /data/local.prop
exitabd reboot
adb shell mount -o remount,rw /system
adb push su /system/xbin/su
adb shell
chown 0.0 /system/xbin/su
chmod 06755 /system/xbin/su
rm /data/local.prop
exitadb reboot
adb install Superuser.apk
Source:
http://rootuninstaller.com/2012/11/11/how-to-root-amazon-kindle-fire-hd-7/