You will need 400.000xp for Elite rank. Unfortunately the xp-glitches aren't working in the german version, because they cut out the A.C.E.S.-System (so no bonus-xp for completing tasks either). The only thing you'll get is 2.500xp if you played/completed the first R6V.
Here's the fastest way to get XP regulary: With 6 players (including yourself) start a PLAYER MATCH (advantage over ranked: you can start a new game instantly) on TEAM LEADER and take a small map like CQC-Training. Run over to the enemy team and shoot them all.
1 Round takes 30 seconds and will net you:
3x 18XP for the kills
1x 121XP for killing the enemy leader
1x 121XP for winning the round
Using this setting it will take roughly 10-12h to get the Elite rank from zero.