A word of caution on higher mileage transmissions like yours, Doru. Changing the fluid out can cause failure of the transmission as the new fluid will loosen up all the crud and may block valve bodies, etc.

I'd recommend proceeding with caution. At the very least, drop the pan, clean out the crap, and put in a new filter.

The fluid replacement process is available onsite, but basically, pump the new fluid in until it runs out the fill hole. Start the X and run it through the gears, pausing at each one (you don't need the wheels to turn, just the transmission to be shifted to each gear). Now the "fun" part; with the engine still running, remove the fill plug and pump in fluid until it runs out again. You'll be right by the screaming hot cat so it's loads of fun. Temp of fluid should be 85 deg F +/- a smidge to be right. I'll just assume you leveled the X5 (not the bottom of the trans, the vehicle itself) prior to filling the trans.

Good luck and let us know how it goes!

__________________
Kirk
Las Vegas
2016 X5 40e Mineral White/Black Dakota Leather, ZLL, ZCW, ZDA, ZDB, ZPP, multi contour seats, rear side window shades, HK stereo
2011 E90M3, 6-speed manual