Do you want the whole thing on your HD or just part of it (i.e. expansions?)
If you want the whole thing on your HD:
Copy the entire SSD\Origin Games\Battlefield 4 folder to your HD\Origin Games.
Rename (or delete) the one on the SSD (if you don't do this it will keep accessing this location because in the registry that's where it's pointing regardless of Origin's settings)
Change Origin's settings to install games to the new location where you copied HD\Origin Games
Click Download on BF4 (may need to relaunch Origin).
It will accept your current files nad not need to redownload them, it will jump straight to installing.
*edit* Do a repair for good measure once finished.
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If you want part of it on the SSD and another part on the HD, a soft link/junction is needed:
mklink /J <Link> <Target>
mklink /j D:\BFxpacs\Xpac# C:\Origin Games\Battlefield 4\Update\Xpack#
http://www.sevenforums.com/tutorials/278262-mklink-create-use-links-windows.html
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*edit*
If your SSD is already full, Origin will not let you even attempt to install new things even though you have a soft link in place. The only way to get around this is to juggle the installs locations.
What I mean is install it completely on the HD first (using the top method so you don't need to redownload everything)... then copy it back to the SSD and soft link the expacs.
I did this once because I was using one of my older smaller SSDs and didn't realize what a beast this game is with everything installed.
*edit2*
Another way would be to just free up enough space on the SSD that it allows the install to take place but with a softlink in place it won't be taking up additional SSD space as it will all be going to the HD.
