Want to reinforce what Std states above, and include a few pics; just did my rear shocks in early July 2025 and ran into the same problem of the shock mount lower sleeve/bushing being completely frozen/corroded onto the mounting stud.
(2016 CX-5; 175,000 miles; original suspension).
My solution was to cut off the shock at the bottom, and leave the bushing/sleeve on the stud.
The two upper shock mount nuts came off no problem after a little Kroil soak.
Speaking of the upper shock mounts, mine were corroded severely and large chunks of the mount were missing; 175,000 miles and 9 years of Chicago winter road salt did them in! Replaced the top mounts with new cast aluminum versions; apparently there are steel versions of this part available too. Am going to coat my new mounts with some marine grease for a little protection.
I then used an 4.5" angle grinder with a fresh Diablo metal cutting blade to cut two "flats" into the aluminum body of the bushing sleeve. Since the sleeve was totally frozen to the stud, the flats I cut gave me a large, sturdy area to get a 12" Crescent wrench onto it. I used a long pipe to extend the leverage force of the Crescent wrench, and the stud threads released from the mounting point in the knuckle! (Lots of Kroil used here also).
Here is a look at the flats that I cut:
Then it was off to the Mazda dealer to purchase 2 new lower shock mounting studs, keyed washers, and nuts. Yes, I could have retrofitted a bolt and washer, but decided to replace the original parts. Will liberally apply anti-seize compound to the new stud!
About $60 with tax for the 6 items. Part numbers are:
Hope this post will help CX-5 owners in the future!
Jon in Naperville, IL