It’s actually really easy. But there’s a few tricks that can catch you out. Credits to Overclock.net for the original steps. I’ve modified them as I didn’t find them to work without some tweaks.
1. Figure out where your current Origin is installed (This is found in the Origin application under the Gear Button > Settings > Downloaded Games. For most users, this will be “C:\Program Files\Origin Games”
2. Quit Origin (it minimizes to tray make sure you have exited the app completely), Navigate to the folder in step 1 above, and back up the games to the new computer or an external drive. You will find sub-folders that are named after all of your games (i.e. “Battlefield 3” ) – copy or move these to the new computer or location – this may take a while depending on your setup, my games were ~100gb.
3. Make sure Origin is installed on the new computer. Make sure that you’ve ran the program and logged in, and make sure the games install directory is where you want it to be ( again this is in the settings). Obviously make sure the install location you set has enough space.
5. Initiate a download for your games you want to move. Don’t worry! we’re not really going to re-download all of your games. This next step makes origin do all of the registry entries and game setup. Make sure the download has got to at least 0.01% or had created the folder for the game in the origin games folder.
6. Now QUIT the origin app (make sure it’s not running in the task-bar). Critical: Don’t stop or pause any of the downloads – just quit the app while the downloads are running.
7. Move your games that you backed up earlier into your new Origin Games director (on the new computer). When prompted to “Merge Folders” click yes, and select “Move and Replace” if windows asks to overwrite any files. Wait for it to finish.
8. Open Origin and don’t touch anything. It will initially look like it’s still downloading but then after giving it a few seconds, it should jump to 100%. After a few more seconds, it’ll tell you it’s ready to install! click “install”, and you’re ready to go!