Navigation Update Help Requested

ALL,

I have a 2020 Jeep Grand Cherokee (GC) Overland. It is "trail rated". Very capable vehicle for my present needs.

I need to update the on-board navigation. Here are the issues.

1) I have an old update that I purchased from Uconnect a "few" years ago. I have not installed it due to some issues. This update is has the two (2) "thumb drives", one (1) for updating the operating system, and the other for the actual maps. Main reason that I have not updated is that I am a bit fearful that I will mess up and "brick" system as the instructions are not clear. My dealer says that they cannot help with this.

2) If you search on-line for navigation updates for the Jeep, you get directed to an "FCA Tool Box" app of some sort, apparently also USB based. Uconnect also has a site as well.

3) I just got an email from Uconnect to purchase another update.

Here are the questions:

If I purchase the latest updates from Uconnect, do I need to first install my older update incrementally, or does this new update have all of the past info plus the present ?

What is FCA Tool Box, and should I use that instead ?

Lastly, the instructions in my old update mention that it could take 30 minutes or more to do the map update (not including the firmware update), and they suggest that the car should be running during the update. Does it really take 30 minutes for the update?

Thanks in advance for any help,

Jeeper 7388