1)hit bloodqueen but let the lock gain agro, suggest unholy or forst presence to keep the agro down. or just dot her and wait.
2) being second on the Agro list you will be bitten
3) Get bitten
4) Bite1 - bite the lock
5) Lock dps some and dies to hellfire
6) Lock uses SS
7) Bite2 - bite the lock
8) lock dps some and dies to hellfire
9) Res lock with Raise Ally
10) Bite3 - bite the lock
11) DPS boss till dead.
You should be able to kill the boss and complete blood infusion this way. It is possible with a shaman too but he will find it really hard to die unless he goes in naked. In that case you use the shaman for his hero and bring a plague scientist and its easy done.