There is an incredibly easy way to get this achievement by yourself, but to do it you need the following:
-GH:World Tour Import (No Sleep Till Brooklyn is the song of choice)
-Two mic's (Headset or USB), 1 Guitar and 1 drum set (either RB or GH)
Now, the first step is to set the mics up so they can play the song by themselves, for those unfamilar with the trick commonly used in GH:WT, because the song is all 'talkie' sections, the song can be FC'd on any difficulty by placing the mic near any constant noise making object (e.g. A fan or even the back of your xbox)
Once these mics are set up, start the song as a 3 player band in quickplay+, playing the song with this set-up leads to the completion of two challenges:
-Maintain a 5x Band Multiplier for 54.00 seconds.
-Achieve a certain score (531,000, but this is easily achieved)
The most difficult challenge is the 5x multiplier, but all you need to do is gain star power on your instrument of choice and wait for the mic's to earn some, then pause the game during one of the frequent large pauses in guitar/drum play, resume play on your controller, quickly activate star power on both microphones before swapping attention back to your own instrument, if done correctly you should now be on the 5x multiplier, you may also attempt it during one of the 2 band moments during the song to gain a 7x multiplier but this is slightly more risky on drums.
With the non standard band challenges out of the way, back out to the quickplay+ lobby and remove one of the mics, go back and start up NSTB again, the only band based challenge remaining it to score 530,000 points, and easy feat so long as you conserve star power for the band moments and for the 'more active' ending of the song.
Now the band challenges are out of the way, you can focus on playing the song on each individual instrument, you can simply use the fan trick to complete both vocal challenges, bass should pose little threat to both seasoned players and fairly new players, drums will require you to be on expert, but anyone comfortable on medium should be more than fine with this song on expert. Guitar is definitely the most difficult for the majority of people, but to qualm any fears, the song only rates a 4 out of 10 on the in game difficulty meter, you may have some trouble with the final stars on the score and star power challenges, my only advice for both is to practice the solo, activating star power in the solo is a HUGE boost to both the challenges.
If you need additional help I have added a brief idea of how you should be utilising star power.
Drums, are the easiest to use star power effectively, but might be the hardest to gain depending on your skill, given the repetitive nature of the chart you can pretty much activate it whenever is easiest for you. but i'd recommend doing it on a Yellow or Red/ Kick note combo, as it will be easier to activate without interrupting the rhythm.
Vocals you should use right at the end of a phrase, because you'll still get max points and you have a better chance of scoring more phrases with it;
Guitar can vary, the only real time i can recommend using it is during the solo, other then that it's your discretion really, if it helps play through the song once beforehand and notice where the three-note chords get paticularly frequent.
Bass is hard to explain, here is the path I used-
http://bit.ly/burhkF (if you don't use paths or don't understand just PM me)
And that's pretty much it, if anyone has any suggestions for improvement, anything I can add let me know in the comments =]