Step 1 The elbow escape has it's place in normal submission wrestling and the no rules fighting arena. Important to understand is that in a non striking situation one can allow the person on top to sit up or be close. When striking is involved it is imperative to keep the opponent close to you as your opponent has a huge advantage in leverage, gravity and momentum throwing shots at you when in a upright position. First step is to get one of your elbows based on the inside knee/thigh of your opponent.
Step 2 In this step your objective is to create as much space as possible. In this pic Morne is able to brace his palm and forearm of both arms against his opponents leg. The idea is not to try and make space by pushing your opponents leg away but rather to push your hips (shrimp) away from your opponents leg creating space. This hip movement also known as shrimping must be as eratic as possible. In other words you will have to combine a few bursting hip movements together making it difficult for your opponent to control your hip movement. You also need to turn your hips vertical in relation to the ground to create maximum space and leverage.
Step 3 Once you have created enough space you are able to slide your knee of the bottom leg (the one against the mat as your hips will be vertical) through. You need to continue keep pushing your hips back and block your opponents leg to ensure he doesn't close the gap/space.
Step 4 Once your leg slides through you can release your hands/arms from controlling your opponents leg. You are now in the half guard position and have several options from here i.e. pull guard, sweep, move to the back, submissions etc. In this specific scenario Morné decides to work to full guard position.
Step 5 Hip movement is the most important aspect in ground fighting. And here is a classical example of how important it is. For Morné to be able to pull guard he needs to transfer from his left hip being on the ground to his right hip being on the ground in this specific scenario. This creates the space for him to be able to bring his legs through and gain the guard position. Without effective hip movement this would be impossible.