What's in the pics, media blast it then use a quality epoxy primer. You don't want to grind away rust as it will just thin everything in that area. Media blast then look at the condition of the panel. Very thin, holes etc. require patching. Poke around with something like a sharp pointed end tool of some sort (words are escaping me ATM). If you can poke through then replace. If everything seems solid then you are probably good. Exception would be when you have deep pitted rust in areas. Then replacement is an option.
What I see in those pics doesn't approach replacement level. Actually looks pretty good. You do want to media blast it though. That is the best way and really the only viable way to do it and remove all the rust. (there are exceptions but I mean DIY)
You can get a "spot blaster" very affordably. The time you save versus sanding, wire wheel, etc will pay for it ten fold. You don't need a huge compressor to run one of the small spot blasters either.
Zendex spot baster is a good one
https://www.google.com/search?client=firefox-b-1&sca_esv=596256598&sxsrf=AM9HkKnDt4bkb4gsRfHLhv0j A2fSvSSJjQ:1704577295737&q=zendex+spot+blaster&sa= X&ved=2ahUKEwiDkdGh3cmDAxXaMVkFHVWoAEYQ7xZ6BAgME AE
TP Tools has a good one to.
https://www.tptools.com/Speed-Blaster-and-Hot-Spot-Spot-Blaster-Kit,7206.html
Those would be the only two I'd recommend. Stay away from the Chinesium knockoffs.