Someone please help. I finally got up the nerve to try and install this but I ran into a problem right away. I used to have another partition on my internal sd and now when I just try the first step I have a problem. This is what it says...

/home/user # umount /dev/mmcblk0p1
umount: cannot umount /dev/mmcblk0p1: Invalid argument

I am assuming that it is from the old partition on there but I dont know how to delete or remove it so know I have truelly messed up things. Please help me stumble through this.

Thanks in advance.