Download and install the newest version of OSATE from The current version (November 2019) is 2.6.0.

The BLESS plugin(s) can be installed into OSATE 2.6.0 as an update site by Help -> Install New Software.

Click the Add button. The Add Repository window opens.

Name: BLESS Location: Click Add button.

Check the box beside “BLESS”. Click Next. Read then accept the licenses. Finish.

OSATE will ask whether to restart. Do so.