I follow their instructions. If they can't be followed then why not have it done by them?
Now there are forums that document or discuss firmware upgrades but here's the deal. All of them leave you by the side of the road if the device gets bricked. Well they try but nothing beats me having the device and files in hand to do this for my clients.
For example I used to send out instructions or chat about it over the phone but firmware updates can be so treacherous that if it's not as easy as clicking the "Update Now" button I want to do it for them.
Have the Uniden UTAB430 tablet that requires a firmware update. The company cites LiveSuit.exe as its endorsed firmware flash vehicle. Some wording is completely vague yet Uniden support cannot explain it. I write to inquire if there are other, vetted flash options available. Pertinent images/video are uploaded to a microsoft online folder at: https://onedrive.live.com/redir?resid=1727C265A60F257A!1788&authkey=!AELaw239neWFQjM&ithint=video%2c3GP
Guidance sought

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic