Deactivate One Copy of Blocs on Broken iMac


I previously installed Blocs 2 (or possibly 2.5?) on two iMacs, which both worked fine.

Unfortunately one of the iMacs is now broken. So, I want to install Blocs 2 / 2.5 on my MacBook Pro, but I can’t deactivate the copy of Blocs on the broken iMac.

Is there another way to do this online? I’ve searched the forum, and seen reference to an account, but it doesn’t seem to work and I don’t have an iostore account (my purchase came through ) . There were also some dead links to pages with more info.

Thannks for any help!