db error reinstalling CiviCRM
If you planning to reinstall CiviCRM on separate database than you will need to delete the civicrm.settings.php file which holds all the db settings. 

Since you are using wordpress you can locate the file in one of the place below

wp-content/plugins/civicrm/civicrm.settings.php


or

wp-content/uploads/civicrm/civicrm.settings.php


HTH

Pradeep