This was an awesome transition from back to arm! Check out that short clip above, I get in to this position alot so for me breaking it in to steps and working it in to muscle memory through reps is what helps.
Main points
-Over hook over neck and under hook under arm, over hook Kimura grips their arm
-Stay attached/ hugging on to the arm! while swiveling the kimura grip over their head and driving down.
-Maintain position hugging their arm and lower leg blocking their hip. Pinch knees and extend hips to finish.