Imagine the flow direction
Drain to Source

Set the meter to DIODE mode. To test N-Channel FETs put NEG(-) probe on pin 6 or 7 and the POS(+) probe on pin 2 or 3. If the FET is good you should get some value  between 100 to 500 or even higher, anything less than 100 the FET is shorted.

To test P-Channel FETs put NEG(-) probe on pin 2 or 3 and the POS(+) probe on pin 6 or 7. If the FET is good you should get some value  between 100 to 500 or even higher, anything less than 100 the FET is shorted.

 

Odd number MOSFETs are usually P-Channel even numbered  N-Channel.
FDS4435 would be a P-Channel and FDS4456 would be a N-Channel MOSFET

Make sure the CPU is removed or many n-channel fets will read shorted.