The main things to watch for are putting on the cam holders, and watching the new RTV seal on the timing cover. Where most people end up having to re-do the job because they skip steps. Sometimes the new chain will look different in markings than the old chain, so always compare the old and new side by side while they are out of the vehicle before installing the new parts.
Good time to do the VCT solenoids and water pump as well.
No the engine does not need to be out of the vehicle, and yes it IS wedged in there. That is why it is listed as a 14 hour job. Go in thru the fender well after removing the liner, take your time. Even the pros are allowed to charge 14 hours book time.