How to delete files from an over full dropbox without upgrading

hello,

While doing a backup of my PC to a local hard drive I inadvertently accepted a trial offer to upgrade my dropbox account from basic to the next level. The backup files (8 gig) were somehow directed to dropbox. I didn't want the dropbox upgrade, and didn't pay for it when the 30 day trial period ended.

Since I didn't pay for the upgrade, Dropbox has reverted to the basic level, but is overfull with the 8 gig of backup files.  I want to delete the backup files, but can't seem to find them for deletion.  Dropbox just keeps asking me to upgrade, which I wont do.

So my question is, how do I locate and delete files when the dropbox is over full?

    Thanks