The first entry begins with a basic deep half guard position, with the inside hook under their ankle, completely controlling their leg (as outlined in the basic deep half guard tutorial!). Once you feel like you have sufficient control, elevate your partner's leg (let's call it their right leg here) enough so that you can bring your right foot in front of their knee, but keep your right knee behind your leg (this is very similar to an X-guard position).

Note: By elevating your hips here, you can bring your partner's foot forward, making their leg not only extremely light but also bent. This detail is outlined in the advanced waiter sweep tutorial, so if you get stuck here or want more details, check that out.

Once you've got your partner's leg elevated, all you have to do is kick your legs straight through, crossing your ankles (or making a triangle if you're newer to the position), and you're almost to 50/50. You need to pass their foot to the other side of your body, though. Once there, use your hips to turn your partner's knee outward (closer to a triangle here) while blocking their other leg with your right arm, keeping them from crossing their legs to defend the position. Lift your hips and keep your knees wide to finish the heel hook here, preventing the roll.