The Islandora Solr module provides a way to configure the Islandora search functions, the search results display, and the display of metadata on object pages.
In order to use the Islandora Solr module, Solr and GSearch must already be installed and working. See the tutorials below for instructions.
Chapter 4 - Search & Discovery in Islandora
Upgrading From Older Versions of Solr and GSearch
Install as usual, see this for further information.
Configuration settings for the Islandora Solr Module are in Administration > Islandora > Solr index (admin/islandora/search/islandora_solr).