1. Add [[language]] in sql and settings.php
2. Remove .defualt from all language files in the package /languages/ folder.
3. Rename the /favicon.ico.default to /favicon.ico
4. adcopy_pubkey, adcopy_privkey and adcopy_hashkey are same for all installation.

Note : As mentioned in the upgrade notes (i.e. readme.html) the old template is not compatible when upgrading from versions lower than 2.0
Below is the extract from the upgrade notes :
Either update your template to work with the latest version or navigate to /admin/admin_config.php?page=Template and change the template name to "bootstrap"

5. We have disabled the upgrade because upgrading from pligg 2.0.2 to kliqqi 3.0.0 requires migration. and as of now there is no migration notes. http://www.kliqqi.com/migrating-from-pligg-to-kliqqi/