I got a coolant flush kit from peak for like 5$ and it had all directions on the bottle. You do not need to take the thermostat off unless you are going to replace it. You will just need to leave the bleeder screw on the waterneck loosened until there are no more air coming out of it, just liquid. you can start the car with it closed, but once you start to circulate coolant then just crack it open a little bit until you see fluid a couple of different times. Just make sure to rinse several times getting it up to temp and running it at temp for a while to make sure that you do not mix coolants(this is critical) Also when filling the radiator back up and letting it circulate getting all of the air bubbles out, make sure to leave the coolant cap off of the radiator which will allow the air to escape. Just make sure to keep an eye on the level, as it will go down once it starts to fill the system. The petcock drain is on the bottom of the radiator on the drivers side. It turns about a quarter turn only and then pulls out to allow your coolant to drain.......Hope this is enough to get you started. I know on my coolant flush I had to do the following:
1. drain all old coolant out of system as much as possible
2. rinse as much as possible......when running pretty clear seal system back up and get up to temp. drain all fluids again.
3. fill levels up with water and coolant flush liqued(about a quart) and run at operating temps for 4-6 hours
4. drain flush liquid, rinse, fill with water get up to temp.
5 drain water, finally refill with coolant/water mix
