For a CCRC installation with a recent (3.4+) Eclipse, you should follow this technote.
The link you are using is to add ClearCase (as detailed in "Rational ClearCase SCM Adapter (For Eclipse), Version 7.6.0.0"), not CCRC, to Eclipse, and it won't work anyway, since you don't have ClearCase on your workstation.
Warning: See "System Requirements for the ClearCase Remote Client".
It only reference Eclipse3.x, no Eclipse 4.x.
An Eclipse Juno 4.2 might be too recent to support a CCRC plugin.