Double-click the round layer to unlock. Because the layout below is not enough for me to pull legs, so use
Cut the tool to extend the layout down (pull out of the layout), as to how many ends you want to stretch your legs.
Rectangular selection Tool, Circle leg range.
Menu select "Edit ➜ content awareness ratio" to pull the warp area down to full version. Then enter to determine, Ctrl+d deselect the range.
Finish the second step directly ctrl+t down is also a way, and faster, but if you encounter the problem of natural convergence, or obediently do the above steps.