This short tutorial will teach you the basics of context handling and switching for multithreaded applications.
Simply calling:
Display.releaseContext();
will release the current context from this thread allowing another thread to make the context current to the other thread. Making the context current to this new thread is simple:
try { Display.makeCurrent(); } catch (LWJGLException e) { }
will cause the current thread to have ownership of the context, and thus GL calls can be made from that new thread.
Warning: Making GL calls when a context has been released but not yet owned causes a NPE to be thrown.
One simple example of using this mechanism is if the renderer of the game is on a different thread than what makes the display; releasing the context after display creation and making it current to the renderer thread before the rendering thread starts is just one usage pattern.