How do I wire up a saeco magic deluxe coffee grinder to be a standalone coffee grinder?
I can see two motors. They have a 2A fuses on them and most likley are just normal brush motors 10vdc~15vdc
I know this because there are only 2 wires to both of them. Stepper motors use 4 or more wires and need special circuits to make the motor spin. There are some that use 3 wires that might also require a special circuit.

Unfortunately there is no indication what the transformer supplies to the PCB and also there can be voltage regulators there where the big heat sinks are. So the motors could also be 24vdc motors.

You need to use a multimeter with DC and measure the two wire points on the motor when its running. That will tell you how many volts it is.

Then all you need to do is supply those motor with the DC voltage you measured, times that by 2 (2Ampers) and make sure your power supply can handle the load.

For example- 


24vdc * 2a == 48watts maximum power
12vdc * 2a == 24watts maximum power


I really doubt the motors are AC driven.