To replace the radiator hoses, you should only need to remove the pressure cap from the expansion tank and open the radiator petcock which is on the lower corner on the passenger side. It's plastic and there is a protective recess the petcock sits in. The lower hose is pretty straightforward to remove with the clamps being the spring type. A set of water-pump pliers is all you need assuming somebody has not replaced them with the screw-type clamps.
If the hose does not want to twist off, use a box cutter or razor knife to slit the hose and peel it off. Be careful to not cut the connector on the the radiator as the end is plastic.The factory clamps are strong and you should be able to reuse them.
If you are replacing the 3 upper hoses (a good idea BTW!) you should inspect the metal tee fitting for any corrosion or rust. You can clean the outside by sanding and repainting. The inside can be cleaned of any junk with a plastic bottle brush.
Once the hoses are back on, open the bleed valves (one is on the driver's side of the throttle body and the other is on the thermostat housing) and begin to pour in a 50-50 mix of distilled water and green ethlyene glycol antifreeze. I fashioned a "bib" from aluminum foil around the bleed valves to get coolant to run away from the Opti. At some point, a coolant stream will flow out of the bleed valves and you can close them at that point.
Continue to fill the expansion tank until the mix is up to the bottom of the filler neck. Start the engine and let it idle until the thermostat opens. Keep an eye on the temp and if it hits 210 without the water level dropping, shut the engine off and let it cool then restart.
When the stat opens, run the RPM's up to around 1100-1200 and fill the expansion tank to just under where the cap seal sits. Install the pressure cap and shut the engine off. Check the overflow tank for the proper level of coolant.
Don't do any full throttle stuff until the coolant temp cycles from cold to operating temp to cold for a total of three times. This should bleed any trapped air from the system.
If you see overheating after the refill process, you may have to re-bleed the system by opening the valves and adding coolant at the expansion tank.
