Grace does not need any special installation, because it is a plain ECLiPSe library with some Tcl source files. It is either already present in the ECLiPSe distribution, or it was obtained separately as grace.tar.gz file. In the latter case, the file should be gunzipped and extracted in the ECLIPSEDIR/lib/grace directory (or in any other directory in the library_path or its grace subdirectory).