E70 N62 Rocker Arm Fallen

[e70jane]

Been chasing a hesitation problem for the past 6 months. Multiple CAN faults and cel are present. Stealership replaced negative battery cable and ibs but no difference. Searched all over for a short but couldn't find any. Replaced alternator, pointless. Checked Vanos, all working. Replaced driver side Valvetronic actuator due to fluctuating ohms value on multimeter, wasn't the problem. Finally, what I hoped not to perform, replace eccentric shaft sensors. So today I removed the driver side valve cover and removed eccentric sensor. Nothing unusual, connector and beneath the square metal plate was free of oil. However, I discovered a fallen rocker arm. Now I'm quite confident that all along, this was the culprit! Now, how bad of a job would it be to reinstall the rocker piece?