See here if you need to upgrade from free to PRO version: Upgrade Free to PRO version
First of all, make sure you have purchased the PRO version and downloaded the ethereum-ico.zip file.
Then open the Add New plugin page and press the Upload Plugin button:
Click the Upload Plugin button and choose the ethereum-ico.zip file for upload, then click the Install Now button:
Wait for the Plugin installed successfully sentence, then press the Activate Plugin button:
You will be redirected to the Installed Plugins page. Find the EthereumICO plugin card and click the Settings link in the card.
It will open the EthereumICO Settings page.
Note that you can access the EthereumICO Settings page under a general site settings section too.
See full configuration settings reference here please: Configuration Settings