as I understood the photo shows the TE1 (by Lenz) board which allreads has an integrated DCC decoder (without back-EMF-compensation, type like Lenz LE077XF) but this is not the board in the ICE, only one with similar physical dimensions.
So you will find the standard Tillig analog board inside (if you bought a new ICE from a modell railroad dealer), and can:
1. solder a decoder to the pins 1 to 6 (refer to the decoder's documentation, it's easy)
2. if it is a newer one which allready has the NEM 651 female plug, then you also could plug in a NEM 651 compatible decoder. In this case you should buy the version of decoder with NEM651 plug or solder one on the cables.
For both cases you need to brake out the little analog part of the board, as described in the Tillig manual.
For any other cases you will not need a special platine board, there are only some wires to connect: left and right track to decoder's black and red cable and to the 2 cables from the ICE electrical coupling. Motor to decoder's gray and orange cable. Yellow and red LED's pads to decoders white and yellow cable, LED common plus pad to decoder's blue cable.
And in the case you will find a TE1 inside (don't know if you bought the ICE as used part) then use it as functional decoder for the LED lights in the motorless end.
If there are any remaining questions please feel free ...