Next month I will be upgrading my EF 70-300mm f/4-5.6 IS II USM lens to the Canon EF 100-400mm f/4.5-5.6L IS II USM Lens, I would like to have routine maintenance done on the old lens, cleaning and so on. I have never sent a lens in and was wondering if there is anything special to do? I tried to figure it out on the maintenance page for the lens but they make it a nightmare to figure out how to do anything. Also I may sell this lens to try to get another lens (Canon EF-M 32mm f/1.4 STM Lens as I have never had a prime lens and shoot a lot of landscape and already have the 11-22 lens) (Camera is a eos M50 Mark I) and I would like to know how to figure out I believe it is called shutter count on the lens as I see that as a common question to please selling camera lenses. I hope I am asking these questions properly, I am still kinda new and have never had any of my lenses in for maintenance before. Thank you for any help given.
