The rocker arms may need to come out because that is what it states in the factory service manual, but I think you may be able to flip them up and pull the LMA right out.
Figure the amount of time it takes to change out cams and then add about 30 minutes if the rocker arms can be flipped up and about an hour if they need to be removed. Make sure you have a competent service manual available, or you could just pay me to do it. :rick: