I do not think it really matters what gear it is in if you do not have to loosen any shift rod connectors. Some different types of motors require them to be in a certain gear just so you can reach the connector that has to be removed or loosened.
What does your manual say about connectors?
Is there one you have to take loose on your motor or does it just slip out?
usually you have to shift to reverse to access the shift dissconect lock nut and barrel nut,
DO NOT pull out the lower shift rod or you WILL dissasemble the gearcase to reinstall it.