Had mine done about 2 months ago. Book time on the thermostat is about 3.5hrs.

Cost me $550 all-in w/ my Indy ($95/hr labor).

I'd have gone about it myself, but the EGR cooler sits right there over the thermostat on the M57. Just more than I wanted to chew off at home in my garage. It's easier on the gassers.