2003 4.4i Trans Flush

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Hello All,

I need some advice before I perform the trans flush for my X. Right now it is at close to 85,000 miles, the car drives great and shifts smooth. I'm planning to keep this car for at least 150,000 miles so I'm thinking to do the trans flush but I need input from the pro this this forum.
1. Should I use ZF fluid or Red Line (I can get red line from red line dealer near my house).
2. Should I drop the pan, clean and replace the filter or is it ok not to drop and just drain, replace, drain every 1/2 qt from the radiator hose that going back to the trans and replace until you need the new fluid coming out?
3. Have anyone done the complete flush where you take off the hose from the rad back to the trans and drain and refill every 1/2 qt? How many qt total should I need?