How do I correctly load a refill for a 5.6mm Sketch Pen (Africa, Asia, Europa, America, Demonstrator)?

To change the lead, point the tip upwards and press the bottom making the residual lead fully retract into the pen body (fig. 1). Unscrew the bottom counterclockwise (fig.2) and extract the lead (fig.3). Insert the new lead and screw the bottom back, pulling out the lead of the desired size. Inside the caseback there is a sharpener. Let the mine come out for about 15mm, unscrew the case back and hold it on the closed side, insert the lead inside the case back and sharpen it with a rotary movement combined with light pressure (fig. 4).