OK, first you need to format your Micro SDHC card.
Protip: Use Panasonic SD Formatter 3.1 (use Google to find and download, it's free) to format your Micro SDHC card. Use the default settings the program uses, unless of course, you run into serious issues down the road. If you do run into ROMs not booting or glitching or saves becoming corrupted for no reason at all, then feel free to change the settings of Panasonic SD Formatter 3.1. Some people like to completely erase their Micro SDHC card (this will take longer than 10 minutes) as a way to combat the issues I just mentioned, so if you fit that category you know what to do in the future. Fact, Microsoft Windows isn't exactly designed to format Micro SDHC cards, even though it is capable. Next, put the acekard 3.0.0.5 update file on your Micro SDHC card along with the other R4 kernel files. Then you can go forward with putting the Micro SDHC card into your R4, and the R4 into your DS Lite. Highlight the 3.0.0.5 update file and then press the "A" button. This will initialize the update program. When you have the program now open
don't press the "A" button to start the "actual" update until you switch out the R4 for the Acekard 2i (along with the same Micro SDHC card that was just now in the R4 flash card.) Now that the Acekard 2i, along with the same Micro SDHC card is in your DS Lite go ahead and press the "A" button to start the actual updating of the boot loader. Once it says completed and successful, go ahead and use the power switch to turn your DS Lite off. Now you can put all the Acekard 2i files (AKAIO) back onto your Micro SDHC card and you can erase the 3.0.0.5 update file. Your card is now brought back to life and is compatible with Nintendo's 3.0.0.6 firmware. All in all, it's very easy.