How do you manually update the OCLP first so I can install Sequoia 15.5?

I am running Sequoia 15.4 , I am booting to 2.3.2 and don't want to have to completely reinstall my 2015 Macbook pro to bare metal and start the upgrade, which I did the one time I finally moved from El Capitan to Sierra to High Sierra -- auuugh!

Awful

I need to make sure I am on the latest 2.4.0 so I can properly update like macOS is currently prompting me.

Thanks