ALTER TABLE 'tableNameHere' DROP FOREIGN KEY TAG tagNameHereTo add a relation:
ALTER TABLE 'tableNameHere' ; ADD FOREIGN KEY TAG tagNameHere ; REFERENCES parentTableHere TAG parentPrimaryKeyTagHereYou'll have to create all the primary keys separately (the syntax is not exactly the same as for Index On... Tag), and I assume you're destroying the .cdx files and clearing the zero bit on the 28th byte of the table header, and are also removing the primary key entries from the binary memos in the dbc.