When installing RX, there can only be one tier available at any time (Elements, Standard or Advanced). Please note that current versions of RX don't offer standalone versions for the Elements suite. Therefore, the following only applies to RX Standard & Advanced.
If you wish to trial or switch your RX standalone to another version you can follow the steps below:
1. Make sure the intended version has already been installed to ensure necessary resources exist, you can do this from your iZotope account or Product Portal.
2. Open the RX standalone application.
3. Open RX Preferences > Licenses & Updates > Remove Authorization (if available).
4. From the dropdown menu on this page, change the value to the desired tier.
5. Restart RX and you will be prompted to authorize again (click "Continue" to begin the trial).