I recommend keeping the armrest. It can be used in conjunction with a lower center console.
After you cut the foam and cut the bracket like Kunar said, you only have to take the remaining flap of fabric and tuck it down and tighten it. If want it to look even better, you will need to get a seam ripper and carefully cut the right parts of the seam out, you can then re-sew the flap in a way that won't be noticeable unless someone knew what you did to the seat.
Go to a junkyard and cut the plastic clip off of a similar style seat. It's that long thing that is sewn onto the fabric that clips onto the seat frame to hold it tight. Attach it to the flap that you sewn down and use that to hold that part down even tighter.
I learned all of that just by going to an automotive upholstery shop and asking questions. They are normally happy to show you what's required to do a professional looking seat modification.
Edit: I have Gen 3 seats, I don't know, offhand, how much difference there is between mine and a Gen 2's.