Wanted to chime in with how we've done it (completely remotely)
I have a large number of 2024p/2048p switches that we deployed last summer with 6.3.0.15,16 or 18 and CPLD 13. I was looking over the notes for the upgrade to 6.3.2.7 and trying to figure out the impact of the CPLD update from 13 to 15. The language of the patch notes is not worded as strongly as most of the other content, they mention you can upgrade it where for other components they tell you that you must upgrade it (like boot code), but that you MUST downgrade it to go backwards. In addition, they requirement to visit every switch and connect directly to it/power cycle it locally is a gigantic burden. Its it required to update to CPLD 15 at the same time as upgrading to 6.3.2.7?  Is is possible to go to 6.3.2.7 and stay on CPLD 13 until someone can go to each switch and do the CPLD update (weeks or months), or should we stop at some lower release, like 6.3.2.6 that did not yet have the CPLD update until we can schedule the visits?
N2000 CPLD update