See image on bottom for clarity.
Torque = Force x distance
T = F x L
F x L = Fp x Lp
( F x L ) / LP = Fp
Fp = force on pin
LP= Length from rotation
Determine whether you have single or double shear, then use one of the following links to calculate the shear in the pin.
Single Shear Pin/Bolt Calculator
Double Shear Pin/bolt calculator