How hard is it in what way? Physically? Just remove a few screws, slide open the case, remove a backing plate, and press it into a slot. If you really want to get fancy, hook up the wire for the LED light at the front of case. Easy. Even if you've never installed a card in any computer before, there's 10,000 videos on YouTube that show you how to do it.
Now setting up the software, partitioning, configuring with HDToolBox, etc., that's a whole other can of worms. :lol: