Okies , this is an Mitsubishi 6A13 SOCH 24v intake plenum frum a 1997 Mitsubishi Galant 6A13 2.5 . Mitsubishi 6A1 and 6G7 engines have the same SOCH 24v heads and intake manifolds and plenums. So this will be the same for the USA Mitsubishi 6G72 Galant.
In the first pic , the red circles are where screws that need be removed. the ones on the far end of the plenum are nuts and the rest are bolts. All with a 12MM socket. The arrow is pointing to a far off one. The red coloured bolt is on most models and is bolted to a brace bar on the secondary stabilizer . On the 6G73 and 6G72 it bolts to a bar that connects to the engine mount.
In the second pic , the light blue circles are where the throttle cable and body ground wire bolt onto (10MM bolts) . The dark blue circles are where there is an plenum support bracket bolts to the back of the intake plenum , also 12MM bolts. The red circles are for the 2 (12MM) bolts that secure the Exhaust gas bypass pipe frum the exhaust to the intake plenum. Standing in frunt the vehicle , on the left side the plenum will be a bracket with secondary air bypass valve , and other solenoids which will vary for american models but they can stay on the plenum , juss disconnect the wiring and vacuum hoses that leave the plenum completely and the cruise control vacuum actuator hose.
On the last pic the red circle , is on the opposite side of the plenum , . its a 12MM bolt for a plenum stabilizer bracket.
Usually i unbolt the throttle body frum the plenum , doing away with the hastle of undoing the coolant bypass hoses that goes to the throttle body on models that have them. Make sure not to loose the thin metal gasket that seals the EGG connector pipe when removing the bolts