Eggbeater pedals have either a 6mm Hex, an 8mm Hex, and/or 15mm wrench flats (for the eggbeater c only). Note that the right pedal has a standard right-handed thread and the left pedal has a left-handed thread. For identification, left pedal has a small "L" on the spindle or a small groove around the spindle flange. The right pedal has a small "R" stamped in the spindle or no special markings.
Grease the threads and then tighten the pedals to 25 to 30 foot pounds torque (34 to 41Nm) with an 8mm Hex.