DS is easy, very easy to hack. You will have to purchase a slot 1 microsd adapter though. That also implies that you need a microsd card. Bricking is basically impossible, unless you use a program like flashme, but I'm pretty sure you need to take apart the ds in order to install that. Just google NDS homebrew, or go here for more info. That is what I did about a year ago, and everything has basically been fine since.
I just realized that you said DSL, and not DSi, but the info should be out there.