cillik,
Looks like the front bumper cover has to come off. The sensor is behind the rectangular indentation under the front license plate. Removing the bumper cover is not a huge job and it is well documented on YouTube (and HoustonSpeedFreaks, and there could be some links in "intercooler swap" threads on this forum) under "Explorer intercooler removal" (or Explorer intercooler upgrade). From watching a couple of these videos, here are some pointers: take your time, don't force anything, use proper trim removal tools, and have some soft blankets on the floor in case the bumper cover gets away from you. Have a buddy help you as the cover gets more loose and is near ready to separate from the vehicle. It is not heavy but awkward to handle.
HTH.
ETA:
Here's a link to "Explorer - removal and installation cruise control module (CCM)" - LINK.