You could actually run all the upgrade scripts manually. They are located under siteroot/Setup/applications/mojoportal-core/SchemaUpgradeScripts/pgsql
After running them manually you would need to insert a row in the mp_schemaversion table with
insert into mp_schemaversion (applicationid, applicationname, major, minor, build, revision)
values( '077e4857-f583-488e-836e-34a4b04be855', 'mojoportal-core',2,2,3,6);
or whatever version you upgrade to.
Hope it helps,