Migration of stores with the same URLs
After you've provided Source and Target store URLs and performed Demo migration, you can not start new migration with the same store URLs. In Migration Wizard you will receive a notice and will be redirected to the previous migration steps. You will be able to edit current migration settings, or provide new store URLs.
If for some reason you have to perform another migration with the same store URLs after Full migration was completed you have to request for Remigration service. Note that remigration requires clearing all the data that was migrated into your target store during the initial migration. In case you have some new items on your Source store that you want to migrate after Full migration is complete, you can use the option of Recent Data Migration.