Toyota Repair: MIL came on, toyota sienna, step directions

Question
I just had my 2000 Toyota Sienna (Eng 1MZ-FE) tested due to the MIL coming on and the code was P0301 (Cylinder #1 misfire detection).  The light just came on yesterday and it sputters a little after starting and the idle is rough at times.  On the highway it did not seem to do it as much but still surged a little at times. It has 132,000 mi and the plugs were changed in 2004.  Could this be something I might address?  Potential costs involved?  Any first step directions would be appreciated.  

Answer
Most likely the coil that fires Cyl #1 is NG.
Cyl # 1 is the towards the firewall in the front of the motor.
You should be able to cange it yourself.
If you want to be sure. swap the coil to another cyl. and see if the code follows.
po302 is cyl #2 p0303 is # 3, etc.


Mike