Hey guys, I am following this guide you linked to do exactly as he has done but it redirects me to a guide I am already aware of that requires a flash card. I am running version number 4.3.0-4U on an o3DS. Is there any non flash card way for me to go about this? I need to mod this old one to roll back the version of my new 3DS apparently. I have decided to go through this long process, but I am at a wall if I require hardware to update this 3DS. Thanks!
Your browser version is too low to take advantage of any browser exploits. Sorry. The easiest and cheapest thing for you to do to get CFW working on your old 3DS is to get a cheap DS flashcart and follow this guide
to update to 9.2 properly. I found some DS flashcarts online compatible with your 3DS for around $9.00 plus free shipping, and there might be cheaper ones out there. I didn't look very hard. There are also a lot of good DS games out there, so a DS flashcart is a nice thing to have anyway.
Alternatively, you could use a retail 3DS game to update your 3DS to something between 9.0-10.7 (you still wouldn't have an exploitable browser), and then you could use an alternate entrypoint
(anything on this list that requires a specific game and is compatible with whatever version you update to) to get everything setup, but it's likely going to be more difficult and more expensive to go this route. If you don't know what you're doing, you might also make a mistake with this method by, for example, updating to something too high.
Additional info: I see the chart shows that I have to do the MSET way because I am at revision 0-4 and my browser version (in settings in the browser) is 1.7455 - is there any way to update just the browser so I can run the Freeway Browser update instead of getting a flash card? Thanks again for any help.
No, you can't.