If you are already having YMME standard version in your site, no need to do again admin setting for this module, you can keep using existing attributes, attribute set and cms page.
Step 1: Rename or delete Ymme folder and Kamtech_Ymme.xml file in the following respective path from your server app/code/local/Kamtech/Ymme and app/etc/modules/ Kamtech_Ymme.xml. Refer below screen shot.
Step 2: After Renaming or deleting the above mentioned file and folder you should have to clear cache of the site. Admin Panel – System- Cache Management – Select all Check boxes– Flush Magento Cache
Step 3: Take Ymme and Kamtech_Ymme.xml from the received upgrade package, then place that file and folder in the following respective path in your server app/code/local/Kamtech/Ymme and app/etc/modules/Kamtech_Ymme.xml. Refer below screen shot.
Step 4: Clear cache again using Step#2
While upgrading from Standard to Professional version a Master table will be created in the database of site. The master table name is year_make_model_engine_master
Only 1000 ymme records will be populated into the master table while upgrading this module. For remaining records, Please import via YMME_Data_Importer module (you can find a package for it from the received package)
For YMME_Data_Importer,Please refer the below link for installation steps and how to use this module. http://mage-extensions-themes.com/wiki/ymme-data-importer/
For any questions or issues, please contact technical support team via http://mage-extensions-themes.com/support/