Coolant leak from valve inside engine compartment?

[Pedrof]

Seems to be the control valve for the transmission cooler

Porsche Boxster Transmission - Page 3

My mechanic changed mine recently. He did not have to pull out the reservoir. He accessed the removal and replacement of the part from below removing a couple of hoses (sorry i wasn't giving attention to the work during that time) and he had to replace the coolant and bleed the system after.