I installed JoomlaMobile and now I can not get to the backend. how to uninstall the component by hand?

Before I tell you what I have done, I will say this. BACK UP YOUR ENTIRE WEBSITE FIRST!!!

Once your DB and website backup is completed, use PHPMYADMIN or whatever DB management tool you use to delete all terawurfl tables from the database. You will also need to delete the row from your com_menu table for the mobile joomla admin menu in components. This is very risky business and I would highly recommend backing everything up first. You can try reinstalling at that point and any files within the Joomla menu structure should be overwritten just like an upgrade.

I had to do this recently because of a fluke server issue so I know it works.