1.
2. Go into the Control Panel and open up "Programs and Features" (for Windows 7) or it's equivalent based off of your operating system. If you're on Linux or Mac, you're on your own for this part.
3. Find Java in the list and uninstall all instance of it with "update 24" in the name.
4. Run the file you downloaded in step 1.
EDIT: They seem to have broken the link, so all of that is bunk now. Parachat has a solution at this website, though. Should work.
After doing all of that, you should be set to copy and paste. If this didn't work for you or I was unclear somewhere, let me know either here or in chat and I'll try to help you through the process.