@ babieshame:
Short Walkthrough:
This removes MyDocs from the file system, but still all the data on partition /dev/mmcblk0p1 available.
This changes the file sytem type in the partition table from Fat32 to Linux. Still all the data there, but you would get an error after boot.
This wipes the filesystem and the data from the partition, you would stiill be able to recover with extra effort, like testdisk data recovery tool.
This will make the partition usable for the system again, but will not access your data, but make it possible to overwrite it.
This actually overwrites the data with the stuff from your optfs and the content of /home, but only the empty folder MyDocs is copied!
This unmounts the partition formerly known as MyDocs now containing the optfs.

The howto continous to create a new partition table, here called 'table' for simplicity to get the partitions mounted for the next reboot. After you wrote the table to the device, you are ready to reboot. After the reboot you simply create and then mount the new file system for the now smaller MyDocs partition.

Because you first asked about the cp command i guess there is no MyDocs existing any more. Continue like suggestedin the post above with the howto from the "mount /dev/mmcblk0p1 /mnt"-step to achieve a working setup. right now you are in the middle of nowhere.