Multistore Search Fields
Backup your database and site
Make sure you have a complete backup of both your Magento database and your installation files. The changes are small that a problem during installation causes a big problem with your installation, but it is always good to have a backup available where your can rely on.
Disable Magento Compiler
If you are using Magento’s compilation mode on your store, you must first disable it. Go to System->Tools->Compilation. If the compiler status is ‘Disabled’, you are ready for the next step. If not, click the ‘Disable’ button on the right hand side of the screen.
Upload extension files
Unzip the downloaded extension package and upload the extracted files with your favorite FTP client to the root of your Magento installation.
Clear Magento cache
Navigate to System-> Cache Managment. Select all available 'Cache Types', select the mass-action 'Refresh' and click 'Submit' to refresh all caches.
Login into Magento Backend
After your refreshed the cache, you need to logout and login again.
To select the attributes that should be available in the 'Advanced Search' for in your store navigate to: System > Configuration > Genmato > Multistore Search Fields. Here you will find a multi-select box with the attributes that are set to be used in the Advanced Search, select the attributes you want to use per website/store.