I would doubt that this is easily possible as the trial pro version that you download is not a beta version and you are using a beta version of avast home.
The only way would be to remove avast home (completely, registry, etc. you can download the avast uninstall tool from the website), reboot, install the pro trial version which is 4.5.561 (I think) and do the beta update again.
Possible, probably, easy, perhaps not.
