If you're not making drastic changes in size, it's not a huge deal.
Another consideration is the TPMS light/display. A lot of 35's can't be aired up to 80 psi. If you're running at lower ranges, you'll trigger the TMPS which I think triggers at 65 psi from the factory. Plenty of the 295 (11.5") wide tires can handle 80 psi, but if you're looking at a 315 (12.5") wide you're going need to do your TPMS too.
Like you, I'm not a fan of changing computer stuff myself. That said, I did adjust mine with the JScan. It's easy to use, and written in plain language. You don't need to know any "codes" or abbreviations. Click on the menu you want, find the feature you want to adjust and then make selections from the drop down options. I adjusted my tire size, and TPMS trigger threshold.
The menus look something like this. **This may not be the exact wording. I just got an image from the internet for reference, but it's straight forward like this.
View attachment 79087
If it's still too unnerving (which I completely get), then just keep an eye on the max psi of the tires you're looking at buying.