As you pop off the lip, Start to lean forward as you are bringing the deck up to grab
Once you have the grab and are leaning forward extend your legs and arms while keeping your legs together
Once you have the extension, Start poushing the scooter down and bringing your legs in and putting your hand back on te bar.
Keep trying at it, getting them dialed right doesn't happen overnight. The more and more you do them the easier they get.
Practice practice practice is key.