Just gather a giant spaceship of goop form earth, pack it tight with as many different bacteria and viruses as we can scavenge from as many hostile places here as we can find, shoot the sucker at the planet, and wait a few million years.
And, while waiting, we can giggle about the new peoples on that planet in years to come, as they explore the ruined mess of their nearby blue-green neighbor, theorize over what might have wiped them out, and try to come to terms with extra tricky new question of "where did we come from"?

Really a cool idea, but the mission planners need to read Arthur C Clarkes' 'Rendezvous with Rama'. In this series Clarke outlines his alien's 'Rule of Three' concept. To ensure a space mission, the architects must send three times as many assets as required, in three different vehicles. Without this redundancy, the mission will fail. This does not even address the fact of repetitive precise landing factors. I go with MIT's analysis as a minimum requirement.

Not sure about their oxygen problem? If they have a balanced eco system then the oxygen produced by the plants will be used by crew and they will produce CO2 which the plants will re-use. The carbon that gets fixed in faeces etc. could be burnt or microbes used to recycle back into CO2 etc. Just balance the system, its possible or we would not be alive here on earth! Adding insects might also be a solution, with the added bonus of a protein source!
The only thing would be if the suns energy is strong enough to support the colony?

Are they gonna take chickens and geese like they did in First Men in the Moon? Or at least take eggs

Everyone's over thinking the problems. Some of us have been a this mars colony stuff for decades. Oxygen: Remove the excess O2 with a hydrogen fuel cell making water. Electrolyze the water to make more O2 if you run low. Farming in the habitat: small plastic pressure tents with elevated CO2. Plumb or tank transfer the gases before opening to harvest. Lots of spirulina early. NItrogen: Make all rigid disposable packaging from nitrogen rich amides, compressed soy meal/paper and frozen ham. All nitrogen rich, 10-20 % by weight, burn in a catalytic furnace. Eat the ham. Recycle the semiconductor of the diode lights and other electronics. Design them to be recycled easily. Include an edison incandescent light fabrication kit. You can make light globes from burned silk, wire and glass. Heat and light. Diodes are cold so is mars. Add an extra opaiq light pressure tent with the same volume as the other two; plumb any excess or contaminated air into it as storage. Leave it otherwise empty. Till an acre of ground leaving it uneven, and mix in some moss spores add plastic over the top. Pump Atmosphere though a solar heater and into the field. Add some steam. The moss will scavenge nitrogen. Send one lander to the icecaps were we know there is water. Fill a balloon with Hydrogen, another with oxygen. Add a dirigible gondola ballasted with more ice and head to the colony site. Both O2 and H2 are lifting gases on mars. Look for a nitrate/ nitrite deposit. Ammonia is also lighter than CO2. Live off the land.

Send the colony supply ships packed full of MREs.

@christopher - isn't that how we got here in the first place?

@Wesley Bruce: As far as I can grasp it, the team's major criticisms are of essential resupply, not immediate support.

I would say the MIT assessment isn't really valid - Mars is a planet and the ISS is a space station, there is a big difference.
Regarding the spare parts possible problem, I would assume those living on Mars would not be part of the 'throw away society' that we have on earth, I would also assume they would have a good general, hands on engineer that should be able to do more than do black box replacement and refurbish much of what fails.
It appears the MIT people are not thinking or considering their history. If the pioneers that opened up the US thought as the MIT people are there would still only be cities on the coasts. Going to Mars is, initially, going to be like those pioneers and being able to make do and mend is going to have to be one of the foremost requirements of those going.

Wasn't there an article on gizmag about oxygen absorbing material just a few days ago? October 4th I think. Problem solved. Any other questions like radiation exposure? What about the volunteers that change their mind one second after blast off?