The one you have is a bit older, here is the last leak, and it works like a charm,, after powering down the device, make sure you disable fast boot before powering down, if not it will screw it all up "remove the battery for one minute, reinstall, then VOL Down + Power, let the Flashing process finnish, it will take quite a bit of time, DO NOTHING, once it does the update at process number 3 it will take the longest, phone will reboot twice while updating
http://www.talkandroid.com/116546-latest-ics-leak-for-the-htc-rezound-looks-to-be-near-official/ , click on the download link, once file is loaded, go to where the file is, right click on it and remove all the numbers from the front, once you do that right click on it again and send it to the SD card directory on your PC, once you connect your Rezound the PC should show two extra hard drives, one is your internal Rezound Hard drive directory and the other is your SD card directory, once yo send it there, disconnect the phone from PC, now use a file utility like Solid Explorer to check for the Zip.
If you have any questions, just PM me I will run you through it, it is very easy and painless.