Access multiple versions of a package in Java

We have several applications that use Apache HTTPClient 3 to make HTTP requests. Recently we have also began creating web service clients that use HTTPClient 4 for various reasons. The Apache stance is that "major releases are not backwards compatible". While I would love to update all of our projects to use version 4, that's simply not feasible.

So, while my main question is rather general, my particular question is. How can I use HTTPClient version 3 and 4 in the same application? In our case an application can be a web, desktop, or command line app.

I have read the SO question for java-dynamically-load-multiple-versions-of-same-class which seems semi close but I don't care so much about the dynamic part. In fact I would like the JARs to be shipped with the app (example, WEB-INF/lib for web apps) I also see OSGi mentioned a lot in questions similar to this one but it seems to be overkill or perhaps overly complex (maybe a simple example could prove otherwise).

In the end I want to be able to hand a team a set of jars that they can drop in and it just works independent of their project using HTTP Client 3.