There are plenty of threads on this subject already. The replacement battery is an AGM H9. Many people have got new batteries at AutoZone, Advance Auto Parts, etc and done it themselves.
https://shop.advanceautoparts.com/p...m/10866724-P?navigationPath=L1*14920|L2*15000
If you purchase online for in-store pickup at Advance Auto, this weekend (through March 25) you can get a 20% discount, and they may install it for you (you can call ahead and ask).
I know there are some videos on YouTube for 1G Genesis, but not sure about 2G, but probably the same.
Some AV settings may be lost with a DIY battery change, but the only real complaints I have heard was the 2009 in California only, due to California emission testing data that was lost. Problem was fixed by Hyundai in 2010. It's not like the problems with some cars (like BMW) where the car won't start if there is a power loss during battery change (due to security system).