I moved from 32 to 64bit:
After installation, I was given the option to remove the 32 bit version -I was unsure so I kept it.
Next reboot it was back to the 32bit version again.
When I closed that, and launched the 64bit version, I was again given the option to uninstall the 32bit version, and went with it this time. Careful what you click during install - the option to delete previous profiles (or whatever it calls saved jobs) was a bit lowkey for my taste.