Download
Go to http://www.akeebabackup.com/download/admintools/ and then View files.
Download now
Install
In your site's administrator area, go to Extensions >> Install/Uninstall, click Browse to find the file and click Upload File & Install to complete the upload.
Change Database Collation
In your site's administrator area, go to Components >> Admin Tools
Click on Change Database Collation.
It's generally recommended to use "utf8_general_ci". Click Apply and you're done!