As is my habit with such things, here is my experience getting it.
I logged onto my PlayNC account. From there, I went to the PlayNC store, found the mission pack under the Guild Wars stuff, and clicked to buy. It brought up a more detailed description of it, great, click to buy. It had most of my billing info (address and the like), so I put in my credit card information, clicked to continue, went through a nice little bit of authentication, and then finished. It presented me with a reciept type tying and the option to "apply now" which I did. It verified that I wanted to upgrade my account, said yes, and now I'm done! I got two emails; one for payment receipt and one for code application, and I'm all set.
I haven't been onto Guild Wars in a little while, so the game is updating. I'm looking forward to playing these missions, and am hoping I don't need to be an uber player to enjoy them.
Whoah, that was quick. Done updating. There's nothing that I can see that says, "Hi! Bonus mission here!" on the menu or character select screen. I hopped onto Yojimbode Genki ("Healthy by means of Bodyguard") who's at the monestary. I really don't know how to access the content - it would've been nice to have some sort of "Hey, get it here!" type thing. I ask "how do I?" on our Alliance chat channel (yay!), and get told to go to a major city and look for a historian NPC. A quick trip to Kaineng (I love traveling in Guild Wars - teleporting rocks) and I find Durmand, a historian NPC :D
I pick Gwen's story, and there's a nice little book dropped into my inventory. Double click it to open, and it unfolds in your screen; the left page has an illustration, the right narrative. A "enter mission" button is right below the illustration, tempting me, but the thoughts of an incoming pizza stop my from pressing it. Anyhow, I go through, read what's there, and it seems I'm missing pages! Oh! Story to find? I'm up for that. I like the fact your mouse cursor turns into a little hand and you flip the pages - nice touch.
I might get to playing this weekend; so far I'm looking forward to it. I'm hoping that at least one of the four sets of missions will have some of that trademark warped humor I so enjoy ;)