See the hotel webpage at http://doubletree3.hilton.com/en/hotels/colorado/doubletree-by-hilton-hotel-denver-tech-center-DENEWDT/maps-directions/index.html for driving directions and information on other transport.
That site does not detail “getting there” via RTD light rail. To do this from Denver International Airport will take about an hour. The light rail station is at the south end of the airport, down the escalator. This is the A line. You can purchase a ticket from the machines ($9 full fare, $4.50 for seniors). Take the A line to the Peoria station, disembark and follow signs to the R line (just the next track south). The R line will take you all the way to the Oxford station, which is near the Doubletree by Hilton Tech Center. Although it is a short walk from the station to the hotel, it is not smooth, so best to call the hotel (303-779-6161) and request that their shuttle pick you up at the station.
From other locations in the Denver area, remember that your stop near the hotel is the Oxford stop. From Union Station downtown, the E line will get you there.
We will be looking forward to your arrival!