Step 1 -> get an image i used the following image FreeBSD-HEAD-r249996-ARMv6-RPI-B-WIFI-3GB.img.tgz. Open a web browser and go to the folllowing url http://files.khubla.com/freebsd-raspberry-pi/FreeBSD-HEAD-r249996-ARMv6-RPI-B-WIFI-3GB.img.tgz, or if your a command line buff like my self lol :) you can run the following command
Step2 -> Extract the downloaded image
Step3 -> Umount the SD card
Step4 -> Copy the image to the SD card using the dd utility (Unix/linux/Mac) as for windows im not sure what utility to use , but google.com can take care of this issue for you :).
Step5-> Unmount the SD card Again
Once the above steps have been completed, boot up the rasberry pi and bingo you will see the following screen. NOTE: username:pi password:raspberry once logged in you can su to root