Tips/Tricks/Gotchas for Purging/Refilling ATF, Brake Fluid, and Coolant?

[IsleOfMan]

I just picked up an '06 Mountaineer 4.0L AWD with ~137k miles on the clock. The brake pedal seems to have a bit of play before the brakes engage (though they don't feel spongy and stop fine) and the shifts from 2-3 and 3-4 can be a tiny bit hard when under load. I thought, given the mileage, it might be a good idea to drain/flush/purge the Brake Fluid, Transmission Fluid, and Coolant. Also, there's a bit of rotor vibration on braking, so it seems like it might be a good time to go ahead and replace the front rotors and pads too?

I've not got under the hood or under the truck yet, but I was wondering... are there any tips/tricks you guys would care to share on these tasks, especially any gotchas you'd point out to avoid major catastrophe?

Thanks in advance!