how can rename a partitions table with child tables

I am trying to rename parent table in partitions. I created 3 child tables on year wise manner. I can alter the name of parent table but I don't know how to alter the 3 child table references.

This is my structure of partition tables.

CREATE TABLE IF NOT EXISTS test_demos(
id bigserial NOT NULL,  
partition_by integer NOT NULL,
names character varying (80) NOT NULL,
age integer,
aed character varying (5) NOT NULL,
entered_user_id integer,
entered_post_id integer,
entered_office_id integer,
dept_code character varying (25) NOT NULL,
owner_dept_code character varying (25) NOT NULL,
approval character varying (5) NOT NULL,
which inet,
whom macaddr,
who character varying(50),
row_created_at timestamp(0) WITHOUT TIME ZONE NOT NULL DEFAULT 
CURRENT_TIMESTAMP)
PARTITION BY LIST(partition_by);

CREATE TABLE IF NOT EXISTS test_demos2019s PARTITION OF test_demos FOR VALUES IN (2019);

CREATE TABLE IF NOT EXISTS test_demos2020s PARTITION OF test_demos FOR VALUES IN (2020);

CREATE TABLE IF NOT EXISTS test_demos2021s PARTITION OF test_demos FOR VALUES IN (2021);

via Chebli Mohamed