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 ($10.50 full fare, $5.25 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 Orchard 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 Orchard stop. From Union Station downtown, the E line will get you there.
The hotel recommends a limousine service they are using for transport from DIA to the hotel (and returning to the airport): If you can coordinate with other attendees, this might be your best option. The flat rate of $65 is per ride - not per person. If you want to arrange for pick-up at the airport, call Miloud of Capitol Limousine Service at 720-394-6472.
We will be looking forward to your arrival!