I presume you're asking this in terms of a STAR TREK show? I'm not really a STAR TREK technologies buff, or anything. But deflector dishes have been used on starships to push asteroids, starships and other massive objects a short distance (beyond a certain danger zone). Also, consider the size of that ridiculous mushroom-looking spacedock revolving around Earth. Something that huge must surely have its own gravitational influence. Send that after Europa and push it along, like a tugboat nudging a tanker.And how would they move Europa? And what if there really is life there, would thawing the place kill that life?
As for Europa, I have to agree that in the STAR TREK Universe, that icy moon is known to support Life. I personally do not see how Europa could, in reality, harbour even alien microbes. Yes, there's probably an ocean, but it's an icey slush, probably with thermal vents spaced few and far between. Also, in Jupiter's environment, I seriously doubt the chemistry's right for it. But until NASA says otherwise, STAR TREK is free to assume that Life is there. Microbes on Mars were found to easily co-exist with Humans in ENT, nobody seemed worried about them, or brought them up, even. Humanity just set up camp and didn't give it a second thought. I'm sure the same can be said of Europa. And, once moved, if the warmer climate didn't agree with Europa's microbes, I'm sure Starfleet would be accommodating, some way.
But STAR TREK uses technology to beam down, mostly, instead of using shuttles, though they're available. And the same could be said of Genesis technology. The Federation - and Starfleet - would rather use an impactor than move planetoids around. Both will do the job, but the show's got to wow us with what Man can achieve, when he's found himself in the right century, with good resources.
This link even has an over-simplified map to describe how NASA plans on diverting an asteroid to orbit the Moon, should it ever follow through on it:
http://phys.org/news/2013-01-nasa-capturing-asteroid-moon-orbit.html
This one is just an official announcement on the matter by NASA. A very wordy article that doesn't seem to say a lot:
https://www.nasa.gov/jpl/asteroid/asteroid-redirect-mission-20140214/