The tutorial uses 'bwa_base', but I don't see that.  So instead, I'm using 'bwa_mem'.  I choose 'Preview and Install', then 'Install to Galaxy'.  I then select to have it installed in 'NGS: Mapping' tool panel, then click Install.

The page then shows two tools:   bwa_mem, and package_bwa_0_7_7.  Both of which show 'Error' as the status.  Clicking on 'bwa_mem' shows some information with "This repository is not installed correctly (see the Repository Installation Error below)...."