First of all,I did this on my 17 pally who is now 19,soon to be higher :P, pally Oleyhealz. I healed and dps'd on him,their was a 16 Lock with a voidwalker who tanked first half,and 2 hunters. One of them had a boar who picked them up on the second half. To do this,Healer must have dps gear on just in case the group all dies and he will have to dps them down,which is most likely on Luzran if your not 20+.
For the first 50%,the void will tank,He will most likely lose aggro fast so you have to have a hunter's pet pick him up. Since your got 3 dps instead of 2 dps and 1 healer,it should happen in about 30 seconds per fight. I prefer a boar or a bear for hunter and void for lock. Its pretty easy,did it with a lvl 16 healer lvl 16 lock lvl 15 hunter and lvl 17 hunter. Im sure you know which hunter's pet tanked,the boar. Enjoy your rings!