My team has been trying to go "agile" for few releases now, but being part of a large corporation hasn't exactly made it easy. I won't pretend like I have the answer, but I can share some of my observations.
We've been doing that last thing, and although there's a ton of room for improvements, overall our entire team has been very happy and that says a lot, when we are part of giant corporation.
One important thing that we got wrong the first 3 times we "went agile", is each one of those times people were told how to work and they were told what to work on. That's number one way to have your team completely lose interest in the project and then you are in real trouble.
Instead, try the opposite. Tell the team, they can do whatever they want and as a manager/leader (if you are one, if not make your manager repeat these words), your job is to make sure they are as productive and happy as possible. Process is not a bad thing, but process should be there to help your team when it realizes it needs one, not the other way around.
If some of your team members prefer to work in isolation, let them (to a degree). If they prefer to work in pairs, let them do that. Make sure to let your people pick their own work as much as you can.
Lastly, and this is very important and is always overlooked. YOU WILL NOT GET THIS RIGHT (unless you are superman, or at least batman). Having regular retrospective meetings is extremely important. When we rolled out retrospectives, they were done by the book and it felt like yet another process you had to sit through. That's not what retrospective is for. It is for listening to your team, identifying areas that cause the most pain and fixing them so that everyone can move on with their work. Apparently software engineers in general like delivering products and features and the most important message retrospective meeting needs to communicate, is that it is solely for their benefit. You want to identify and tackle obstacles, starting with the biggest ones (or easiest ones, there's some kind of 2D map involved) and get them out of the way so your people get their work done.