Journalist v1.9 is a free theme available to all free hosted WordPress.COM bloggers. See here. THe version of the theme you have purchased is for WordPress.ORG installs which run on different software and it cannot be used here. We run on different software and CSS editing here is theme specific. You cannot use style sheets from elsewhere.
There is no FTP access to free hosted WordPress.COM blogs and we cannot install individual plugins or any themes into them The themes found on the internet are for wordpress.ORG installs which run on different software.
On free hosted wordpress.COM blogs we can only use the themes which have been coded to run on this multi-user software and made available to us here. > Appearance > Themes and no others. We cannot edit either themes or templates on free hosted wordpress.COM blogs. > http://en.support.wordpress.com/themes/editing-themes/
Please post an active link starting with http:// to the blog in question.