Reset mySQL (mariadb) master/slave with GTID replication

To reset and start fresh, do;

1) RESET BINARY LOGS AND GTID STATE:

STOP SLAVE;
RESET SLAVE ALL; (note ALL means we need to reconfigure the master as per step 2)
RESET MASTER; (if it is a master)
SET GLOBAL gtid_slave_pos = '';

2) RECONFIGURE REPLICATION:

CHANGE MASTER TO
MASTER_HOST='master_host',
MASTER_USER='replication_user',
MASTER_PASSWORD='replication_password',
MASTER_PORT=3306,
MASTER_USE_GTID=slave_pos;

3) START REPLICATION:

START SLAVE;