HP MSM firmware upgrade paths. Why is this not prominently documented? What is the recommended p

[Discus]

I've inherited a network with a "cold spare" MSM 760; we have current licensing for software upgrades, so I should be able to do something about this. The "cold spare" is on 5.5.2.0, which is a bit ancient. I'd like to have the controllers "teamed" for resilience, and obviously they're going to need to be on the same version. It's been bothering me for months, and now I've decided to do something about it - but I'm kind of stuck on what the correct upgrade path might be. 

Many of the older "release notes" on the MSM firmware seem to fail to note what the pre-requisite mobility software/firmware version is prior to an upgrade. 

The latest version, however, has a notice in the release notes that says firmware must be at least w.x.y.z (which is helpful). However, earlier "release notes" seem not to document this rather vital information (they spend a lot of page space talking about compatibility with RF Manager, but surprisingly don't seem to list pre-requisite installed MSM firmware prior to an upgrade. 

I'm sure there are others who would like to know which of the many, many different versions of the firmware are required to get to the latest stable version - there should be an upgrade notice that gives the update path prominently displayed with the available firmware downloads - or the release notes should specify this (particularly those called for in later versions - i.e. if I need to get to 6.6.3.0, I can go via 5.7.5.0 or 6.0.3.0), but it does not tell me in either of those respective release notes what the prerequisites are to install those from even earlier firmware versions! Failing that, answers in this thread might help someone "down the line". 

Fortigate does this quite well by detailing the recommended/required update path in the release notes for every update. I'm quite surprised HP don't. 

Can someone please enlighten me as to the recommended upgrade path (in the minimum number of steps)? Googling does not seem to help, so this seems to somehow be "arcane" knowledge! It might be an idea to do this from the oldest available version for anyone else who stumbles across this post in the future trying to answer the same question - particularly if HP don't publish a (complete) recommended upgrade path as a separate document or within each release note. 

Thanks!

Something like 5.5.2.x > ????? > 5.7.5.0 > 6.6.3.0 

[RamKrish]

Hi

Yes, you should be good to proceed with 5.5.x --> 5.7.5.0 --> 6.6.3.0.

[Champ895]

I need the version 5.75 in order to upgrade to 6.6. I already have the 6.6 firmware. Can someone please help me with getting the 5.75 firmware please? I have contacted HP and they said they are unable to get it for me. Any help would be greatly appreciated.