1: i do not know why honda recommends 120k, it makes no sense. generally it is every 2 years or 30k miles so if you loves your car do it every years r even once a year. once you get the procedure down and you realize that 2 gallons of honda coolant at $13 each isn't as expensive as honda atf thn it's easier. remember doing a change is OK if thats all you can do. if you can do a flush it requires some extra steps like taking off the upper radiator hose and flowing water through it with a garden hose. thehaynes manuals states to rmove the thermostat and replace its housing. i also hear people leave the t-stat in and run the engine on max heat til the thermostat opens and the water runs clear. if worried with calcium from the hose, i hear its safe since its only for the flush, all water runs out and yo will be replacing it with new coolant.

2: on an 01 v6 look at the radiator go stright down the middle, there should be a square hole in your bottom fender, if not there is a square piece covering that hole, usually there isn't . anyways if you look from up top or look up thru that square plastic hole you will see a white plastic petcock looks like a plastic wingnut.