Tools required:
#1 Phillips head screwdriver
13mm combination wrench
14mm combination wrench x2
Before continuing ensure the machine is fully cooled and unplugged from the power source.
Remove the top panel. Identify the pressure gauge.
First, disconnect the 13mm fitting from the brew boiler elbow fitting. If the tee fitting rotates, it may help to hold the fitting in place with a 10mm wrench on the tool flats.
Next, loosen the nut holding the bracket onto the back of the gauge. It may help to hold the square portion at the back of the gauge with one 14mm combination wrench, turning the retaining nut with the other.
Slide the bracket off of the capillary tube.
The gauge can now be lifted out through the front panel of the machine.
See also:
LUCCA Tempo: Accessing the Digital Display
LUCCA Tempo: Inspecting the Expansion Valve