I'm trying to update the firmware on a lot of Cisco SPA525 phones to the newest version, but the release notes says I need to bring them up to 7.5.2b first. I cannot find this firmware version for the SPA525 posted on Cisco's firmware download section. The oldest I can find for this phone is 7.6.0.
https://software.cisco.com/download/home/283093853/type/282463651/release/
Any idea where I can get 7.5.2b so I can complete my firmware update path? Thanks!