Hello Bee Prusa DIY 3D PRINTER KIT User Manual page 22

Unscrew the little screw and we can now lower the nozzle until it is touching the table too.
Screw it again and assemble the blower, now we have the nozzles at the same height.
With the extruders on the center of the print bed and with
the lowest nozzle touching the table, take off the printed
part containing a fan. Remove the one pertaining to the extruder
that isn't touching the table.
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