Once your partner selects the lapel grip as their defense (or once they're forced to take it as the only remaining option, as often happens during rolling or competition), you need to recognize that the palm-to-palm series isn't going to work right away. The good news is that the basic control principles are universal. If you're starting with the Kimura grip, you will need to switch your grip so that your other hand threads through here.

In the video, I'm gripping Daniel's right arm with my left hand holding his wrist (initially, anyway). Using this convention, let's use right-left to describe what to do next, as it'll be much easier to describe which hand does what. If you have a pocket grip, you won't need to switch your hands, as the "backwards Kimura" will be much easier to get to. Once you have your left hand laced through, bring your right wrist under their wrist (this will act as a fulcrum, so their wrist bends). Next, cover your partner's knuckles with your right hand. If you get good at this, you'll do these simultaneously, because if your partner figures out what you're doing, they'll try to hide their arm another way, and covering the knuckles early on inhibits this as much as possible. Now you're set up for the finish.