Downloads:

http://www.joomlacontenteditor.net/downloads/cat_view/88-editor
the JCE Home

OR

From me:

Copy this in to the "install from URL"box one at a time

1. http://wk.ai.net.nz/mrepo/addons/joomla/JC%20Editor/com_jce_157_156_package.zip
2. http://wk.ai.net.nz/mrepo/addons/joomla/JC%20Editor/com_jce_157.zip
3. http://wk.ai.net.nz/mrepo/addons/joomla/JC%20Editor/plg_jce_156.zip

Now change your default editor under your user.