You will need 1 Million EXP for this achievement. This takes 100+ hours of boosting and is best done with 8 people however only requires 4. Each point earned is multiplied by 7 and you can make about 10000 EXP per hour.
How to boost: The team at control point 5 always runs to 1 to avoid confusion. They capture all control points along the way while the team at 1 waits. Then the teams take turns neutraling and capturing. The team nuetralizing gets 1 point and the team capping gets 6 or 7 depending on how much the point was overcapped. At 7:45 the teams switch and everybody runs to point 5.
The team with nothing to do can be killed along the way for some extra points but DO NOT kill anybody on the team converting the control points or you will just be hurting yourselves. You then repeat capping and nuetralizing at point 5 with reversed roles.
Your boosting team can decide if they want have an all out gunfight when it comes down to the last 5 or so seconds. If done well both teams should have around 400 points (2800 EXP).