You can change the default Solr index location as well as the default search port.
Configuring a custom Solr index directory location By default, the Solr index is in %TRIDION_HOME%\Search\solr-data\tridion\index. Change a registry key if you want to change this location. Depending on the folder structure you want to have, you may also need to change one or more Solr configuration files.
Configuring a different port for search The default port used for non-secure connections is 8983; for SSL connections, 8443. These may be in use by other Java applications. You can change these ports.