Here's a noob-friendly guide on the gbatemp wiki. You'll be fine, as long as you go through all of the steps in the guide, but just in case you don't want to read through all of it, here's a simplified version (without pictures).
Before starting, make sure your ak2i can run on the 3ds. If an error screen shows when trying to load the ak2i on the 3ds, you won't be able to update, unless you can find another system (preferably a ds phat or ds lite, since those can't block flashcarts) that your ak2i works on. If you don't have any, try borrowing one from somebody else. After ensuring your ak2i can load on whichever system you have, follow these steps:
1) download the bootstrap updater [
here], so that your ak2i can be updated to work on the latest dsi/3ds firmwares.
2) download the latest akaio [
here], which is ak2i's unofficial firmware.
3) read the readme file that is included in the download of step 1, and place correct updater into the root of the micro sd card, depending on the system you are using to update.
4) place the contents of akaio (in step 2) into the root of the micro sd card.
5) boot your ak2i; navigate to where the updater is, and boot the updater.
6) lastly, do as prompted, so that you don't brick your cart!
