Use this tool to generate an XDR transaction to batch trust operations, create a matching buy offer, and royalty payment. The royalty payment is in ADDITION to the buy price, so make sure you have enough XLM!
After submitting, wait 10 seconds then open or refresh the following page:
XDR Test Page
The transaction is only valid for 5 minutes so go submit it quick!
Copy/Paste the XDR to your favorite wallet, then sign and submit.
I recommend Stellar Laboratory: