I think that you hit several of the anti patterns listed here: http://www.jboss.org/jbpm/lists
What steps are you trying in order to install jBPM5?
Is your project a Maven project? if it's a maven project, you don't really need to install anything. Just add your dependencies into the class path and you can start using jBPM inside your project.
For the process designer you will need to deploy it somewhere, you can run the installer and then decide where do you want to run the Process Desginer.
Don't stay here wating for someone to post all the solutions for you, try it by yourself and let us know if you have specific troubles.
Oh sorry, I was not aware of Anti-patterns.
Yes its a maven project. Trying it myself & will let you know in case of issue(s).