downgrading to Marketpress lite

What happens in the future if I am no longer able to continue my membership? Here's what I mean:
Today I build a site with Marketpress. Next year for some reason, I am unable to continue my membership. Since I can no longer get updates to Marketpress, I switch to using Marketpress lite. Since my store is very basic, it doesn't use any features that aren't in Marketpress lite. Could I just deactivate Marketpress and install/activate Marketpress lite?