How to capture an asteroid

Charlie Osborne has a SmartPlanet article about NASA:

Budget cuts may be looming for many departments within the US government, but NASA hopes that the agency can secure a hundred million dollars to capture and study an asteroid.
According to Aviation Week, the space agency’s budget requests for the 2014 fiscal year includes a mission to find a small asteroid and bring it close to the moon through the use of robotic spacecraft. A study conducted for the agency estimates it would cost nearly three billion dollars to bring an asteroid weighing 1.1 million lb. close enough to an Orion crew vehicle stationed close to the moon. Once stationed at the Earth-moon libration point 2 EML2— where gravitational pulls roughly balance so objects can “park” there— the rock, measuring no more than seven meters across, will be captured.
A proposal sent to a National Research Council human-spaceflight technical feasibility panel on 28 March noted that risk to Earth will be minimal, as the asteroid would have the density of a “dried mudball”, and its velocity would be too slow to cause any damage to craft or personnel. Although there will be no danger posed to our planet, finding a suitable target will be one of the most difficult elements of the mission.
If granted, the budget will be divided between human exploration, robotics, and space departments to begin developing the technology required. The mission could give researchers the opportunity to gain field experience, and develop ways to push asteroids off collision courses with Earth if necessary. In addition, some businesses are considering asteroids as a source of metals, so any information that could contribute to this as a possible reality could monetize the project.

Rico says that NASA doesn't want this one to be an 'oops, dropped it on your head', even if it is just a 'dried mudball'...