how to update MLO and u-boot.img in emmc on Beaglebone black

I changed the oscillator on my BBB from 24MHz to 25MHz, so had to rebuild u-boot in order to modify the PLL registers. Hence, I have a new MLO and u-boot.img. I am running the recent debian 3.8.13-bone70. The kernel and file system are fine as-is in emmc. If I look at /boot/uboot/ it appears empty. How do I update just the MLO and u-boot.img in the boot partition of emmc?

sudo dd if=./u-boot/MLO of=/dev/mmcblk1 count=1 seek=1 bs=128k
sudo dd if=./u-boot/u-boot.img of=/dev/mmcblk1 count=2 seek=1 bs=384k