I usually move the folders to my separate partition and then symlink them back into the C:\Users folder. This has the advantage that legacy apps that tend to break on custom paths can access the folder as usual.
This snippet of batch script should do what you want. Note that you have to run it as Administrator for symlinking to work ( untested, YMMV ):
::Change this to the folder where you want to store your data
::Switch to the current user's profile folder
::Change this to the folder you want to move from if you are moving another user's data
for /d %%d in (Documents Music Pictures Videos) do
::Move the folder to the new partition
move "%%d" "%DESTFOLDER%\%%d"
::Symlink it back to the original location
mklink /d "%%d" "%DESTFOLDER%\%%d"
This is just of the top of my head, but it's similar to what I use for my Ubuntu install, where I symlink all of the subfolders of my home folder to my NTFS data partition.