For each platform you unpacked, the executable is /usr/local/lcs-5.2.0/bin/platform/lcs. You may want to copy or move it to some standard place. The man page for command lcs is in directory /usr/local/lcs-5.2.0/man/mann.
Type "lcs" to check if lcs works (exit lcs by ^D). The full installation procedure is explained in the release notes (file /usr/local/lcs-5.2.0/doc/1release.ps).