This is a subtle set of moves that are mostly made possible buy a sneaky bumping out of the hip. You slow the progress by posting your hand on the hip of your opponent but that’s not going to be enough. After you slow their pressure you have to escape your hip away to angle your knee under their stack and against the rib cage. Then you can throw the outside leg over and build a wall to stop the pass.
It takes a lot of practice and timing! And is one of the key drills to building a serious guard defense!