I see this is an old post but I too would like to know how to do that without having to completely log off.
I guess you never tried. You just open the program again, switch the toggle and log into the other version. The 2 versions can run parallel. The only difference is that although the charts and quotes are delayed in paper trading, the trades are still executed in real time/price.
You can also have TOS open in multiple computers at the same time.