Implementing cascading deletes on an existing table

Hi all,

Im trying to find out the best way to implement cascading deletes on an
existing table. I have this:

create table fe_custom_set_card(
custom_set_id int4 references fe_custom_set(custom_set_id) on delete
cascade,
card_id int4 references fe_card(card_id),
card_sequence int2,
category text,
primary key(custom_set_id, card_id)
);

and I want to implement this:

create table fe_custom_set_card(
custom_set_id int4 references fe_custom_set(custom_set_id) on delete
cascade,
card_id int4 references fe_card(card_id) on delete cascade,
card_sequence int2,
category text,
primary key(custom_set_id, card_id)
);

How do I go about making this transition? Dump the data, drop the
table, recreate it and load the data?