Great Article!! Has anything changed for the syntax with v1.0.1 release
Command - cleos set account permission mymultisig11 owner '{"threshold":2,"keys":[],"accounts":[{"permission":{"actor":"partner11111","permission":"owner"},"weight":1},{"permission":{"actor":"partner22222","permission":"owner"},"weight":1},{"permission":{"actor":"partner33333","permission":"owner"},"weight":1}],"waits":[]}' -p mymultisig11@owner