Psychtoolbox locked and svn issues

Having issues with updating Psychtoolbox. Earlier I had begun the process of updating by typing in the requisite command. However, my internet had cut off and the update stopped. After regaining my internet connection, I waited to see if the update would resume but it hadn't. I closed my laptop assuming I could update it all again later. Well, I have attempted to restart the update to no avail as I am met with this error message:

">> UpdatePsychtoolbox
UpdatePsychtoolbox(' C:\toolbox\Psychtoolbox ')

About to update your working copy of the OpenGL-based Psychtoolbox-3.
Will execute the following update command:
svn update "C:\toolbox\Psychtoolbox"
svn: E155004: Working copy 'C:\toolbox\Psychtoolbox' locked.
svn: E155004: 'C:\toolbox\Psychtoolbox' is already locked.
svn: run 'svn cleanup' to remove locks (type 'svn help cleanup' for details)
Sorry. The update command failed:
svn: E155004: Working copy 'C:\toolbox\Psychtoolbox' locked.
svn: E155004: 'C:\toolbox\Psychtoolbox' is already locked.
svn: run 'svn cleanup' to remove locks (type 'svn help cleanup' for details)

??? Error using ==> UpdatePsychtoolbox at 169
Update failed."

Somewhere in there is the option to perform "svn cleanup" however when I enter that command in MATLAB I am met with this:

">> svn cleanup ??? Undefined function or method 'svn' for input arguments of type 'char'."

When I typed in, "svn help command" I was met with:

">> svn help cleanup ??? Undefined function or method 'svn' for input arguments of type 'char'."

My questions are:

1. Why is my Psychtoolbox now locked?
2. How do I unlock it?
3. What is svn?
4. What am I doing wrong?

Still new to MATLAB.