Now you tell me. LOL. Just kidding sort of.

Thanks for all that information, it really is good info.
I wanted to pay Garmin for the map data so that's why I went to the purchase new maps area instead of using Garmin express.
Wow, I was really clueless to this whole process but am figuring it out with help from this forum and the helpful people on here. It is a shame that Kenwood and Garmin are not helpful when it comes time for them to "push" older units behind them, instead of being helpful.
I figured I would at least update my old Nuvi200 if I couldn't do anything else, so the money would not be wasted.

Last night my computer got some bad stuff in it but I used malwarebytes and windows security to clean it up. Today I had a breakthrough and discovered the first "other site" you mentioned (before I read your post) and they are legit after trying three times.
First I had to install a web browser extension which I later uninstalled, then I got something called happy ocean but disguised as another name. It looked like it was doing something when I dropped a file on it. I deleted it later and the third time was the charm. I was able to test my results with a broken Nuvi205 so I used the Nuvi200 and 205 to test things. My 205 wont respond to the touch screen but it boots up and shows the current map installed on the external SD card inserted in the slot. Funny thing is the Nuvi 205 let me go into the touch screen calibrate function by holding the power button on for 30 seconds and when I went to calibrate it I just chased the dot you are supposed to touch over and over again and it never finished. LOL. Both of these units were just sitting in my glove box for years and that's how the 205 ended up this way but at least the 200 still worked. But I digress.

Now I need to find out how much space is available in the DNX 6180 before I do anything else. I have no clue how to do that yet but I am having good luck searching and reading!

So currently I have a usb drive with a folder named Garmin with these files in it.
GarminDevice.xml (from my DNX6180)
gmapsupp.img
gmapsupp.gma (empty dummy file)
gmapsupp.unl (empty dummy file)

This works on my broken Nuvi205 when used with it's GarminDevice.xml file if I put it on a SD card. It just runs off the sd card so there isn't any installation besides putting the card in the slot. Also works on my Nuvi200.

Posts 47 (pg5), 56 (pg6), and 109 (pg11) in this thread are the posts about the DNX6180.

Post 47 the user lists the same 4 files and states that the DNX6180 has to have the update function used. I wonder if these are the only four files needed to update my DNX6180?
The reason I wonder is because the original poster who has a different model has a lot more files listed on his post. I read something about looking through the device xml file to see what options my unit has which might require some of the other files, but I am not sure about this.

Again, I need to find out the storage size in my DNX6180 before going any further.

Post 56 the poster says he updated his dnx6180 as "described in this post" but I don't know if that means the first post or another one like post 47.

Post 109 says he has these extra files (plus what I have on mine) on his usb drive.
/Garmin/XX
- G2S/ xx.g2s
- JCV/ xx.jcv
- PNX/ (no file)
- SID/ xx.sid (7 files)
- SQlite/ xx.db

I wonder if I need these files, and if so would there be only one folder on the usb drive named Garmin and then a folder inside named XX with the five files inside it.

He states "All the xx files, were from the splitting of the unlocked gmapsupp.img file via gmaptool" so maybe I don't need any of them. I don't know what splitting with the gmaptool is for, maybe just something needed if the image file was downloaded from a different source then Garmin?

I have a lot more reading to do!