how do i turn off the alarm to a 4-door 2008 jeep wrangler (hard top)?

You're going to need to take this to your dealer for some analysis. Sounds like the BCM isn't recognizing the key as a valid tool for operating it. You may also have some problems with your SKIM (sentry key ignition module) as well.

I had some problems with my alarm system as well with my 2007. Sometimes, it would simply not arm and/or dis-arm. The dealer deleted the program in the computer chip and re-programed the system. It now works flawlessly. Goodluck

go to the fuse box and pull the fuse. the alarm will be off and if you have keyless entry that wont work either but who needs that?

Try changing the battery in your key. It may just be intermitten/dying. There's a little slot that you can put a butter knife into to pry it open. Just change the battery and see what happens. It just snaps back together. I think it's a CR2302 type Battery

ok, folks here is the simplest fix ***BIG NOTE*** IF YOU HAVE A MANUAL TRANSMISSION, KEEP YOUR FOOT IN THE BRAKE DOING THIS. OTHERWISE YOUR VEHICLE WILL TAKE OFF INTO A TREE OF SOMETHING, MINE DID. NOW THE TAILGATE IS BENT. so the little LED red light is factory installed on the left side of the dashboard about steering column level. I just got it started by holding the key in the start position and by pushing a little black button I found at the bottom of dash below the LED that was flashing.This maneuver reset the alarm and now I can start it over and over without the ALARM stopping me. Just wanted to share this with all that may have this problem in the future.