Notes

• Start by getting wrist control like I am going for a kimura.  That will keep him from basing out on his arm and preventing the sweep.
• The sweep actually is off to the side at about 45 degrees – not straight back.
• Throw your opposite arm across his face over his opposite shoulder.
• Try to hip bump really high into his chest – and drive your knee into his armpit.

If unsuccessful, try to come down into omoplata (untried as of yet):