Oxygen Sensor

Hello all, i have an 07 3.6 Passat vr6 and i need to change both upstream 02 sensors on both sides, is there a DIY on how to accomplish this? Can someone tell me if and what i need to remove and i figured since I’ll already be in there i mind as well change all 4 of them…how much of a PITA is it going to be? Thanks in advance!!