This is an XY problem. You want to know how to add Java 8 to your usr directory, but it's already installable via the Software Center. I haven't found a Linux-compatible version of a launcher for Blackboard Collaborate to test with, and you haven't provided a link to one that I could use to test with. Even then, if one does exist, I don't know if it's just a .jar
file or a native Linux binary. If it's the former, then the solution is in Solus's help center (how to launch Java applications). If it's the latter, then I'm not sure where you got the idea that you need to install Java 8 specifically and extract it to the /usr directory. You haven't given me adequate information to help you resolve your issue.