This mold is featuring an easy print and easy casting setup.
With the M4 screw you can ensure a press-fit for all the casting die parts. It also allows enough leverage to pull out the insert and hold it while taking off the silicone sock.
The insert and lid comes with air holes to reduce/eliminate air bubbles being trapped inside the sock.
The sock itself is also designed to generate additional insulation in between the heater cartridge and thermistor wiring (shorting those line via the hotend will fry your mainboard).
The thermistor will be pressed into place with the sock between the screw and the thermistor.
Additinal parts needed:
M4x8-10 to screw the lind to the insert. (shown in picture)
Use anti adhesive spray for the mold before casting the silicon. I reached good results with baking spray like PAM.
For casting I am using "TFC Dubliersilikon S-ROT mittelhart Shore 33 1 1 HB", but you should be fine with any temperature resistant silicone like e.g. Mold Max™ 60 Silicone.
You will need about 10-15ml as shown in the picture.
I am also using a ultrasonic cleaning bath to shake the air bubbles to the top. Others just attach a ultrasonic toothbrush with some tape to the mold to shake it.
Trimming the silicone sock
Use a scalpel to cut vertically through the lid along the outside of the base
Pull out the lind and insert
unscew the lid and slowly pull it off
Use a sharp clipper to cut off the excess silicone on the seams of the mold.
Flip the sock and use a sharp clipper to cut off air risers