That depends. Cab or open station? The 5P relay is located behind the instrument panel just to the right of the steering column on the open station model. You really need the workshop manual if you are going to work on the tractor.
my 2011 DK45 cab HST had the twin relay under the instrument cover. i had to replace my relay due to occasionally the pto not engaging. after replacing relay..all good to go. the relay part number was T4935-43101 (now superseded by T4935-43102)..