1999-2001 USA Mille Models
Three things:
1.  Airbox de-restriction
2.  Exhaust baffle removal
3.  Wire cutting to access second map on stock EPROM

2002-2003 USA Mille and Tuono Models
Four things:
1.  Airbox de-restriction
2   Remove ram-air duct snorkels (not applicable on Tuono since it does not have true Mille ram air ducts)
3.  Exhaust baffle removal
4.  No wire cutting....seriously advised to get a new EPROM.  European owners can still cut the wire, as their EPROM has a de-restricted map still on the stock EPROM.

All 2000-2003 USA Falcos
Only two things:
1.  Airbox de-restriction
2.  Wire cutting to access second map on stock EPROM
The Falco does not have the exhaust baffles restrictors

How do I do each procedure, if my bike calls for it??

Airbox de-restriction
Click here.  The link is for a Falco, but the procedure is exactly the same for the Mille and Tuono of any year.  The restrictor did change inlet hole size in the 2001 USA Mille, but it still looks the same, and is found in the same exact spot.

Remove ram-air duct snorkels
There are intake runner snorkels or restrictors in the air ducts.  These are located inside the air ducts that feed the airbox, one on each side.  Remove middle side fairings with large Phillips.  Then, with a Phillips screwdriver, remove the small screws that separate the air duct into halves.  Remove the outer half of the air duct.  You will now see a long skinny black snorkel tube.  A single Phillips screw holds in the intake snorkel.  Remove snorkel from inside the air duct, and replace outer air duct, and screws attaching it.  Repeat procedure for other side.

Exhaust baffle removal
Remove the one spring holding the mid-pipe to the collector, just behind your right foot (as if you are seated on the bike).  Remove the single exhaust canister bolt holding it to the rear sub-frame bracket (passenger peg).  The baffle is located in the mid-pipe of the canister section.  Look in the end, and just a few millimeters down you'll see some spot welds.  Grind them down with whatever you can.  A drill and a grinding stone will work just fine.  Grab the baffle with a set of pliers or something similar.  We actually use a spring hook puller.  Using force, pull the baffle out of the mid-pipe.  It takes force, and requires that the welds are broken.  You can use a screwdriver to help you out with breaking the welds.  Again, it takes FORCE and determination............or you could just dump that whole heavy boat anchor and get yourself a slip-on from AF1 Racing.

Wire Cutting or EPROM Replacement
Click here for wire cutting.  Click here for EPROM replacement.  The links are for a Falco, but the procedure is exactly the same for the Mille and Tuono of any year.  Cutting the wire on any Mille, Tuono, or Falco accesses the second map found on whatever chip is installed.  Why don't we cut the wire on stock 2002-2003 USA Milles and Tuonos?  They no longer carry a different second map.  All previous Milles had a second different map (the de-restricted map) on the stock chip.  Later bikes have no second map or they have the same map in both locations.  Either way, you will need to replace the EPROM on these models.

A few notes on EPROM installation.  Line the notch on the chip with the notch on the ECU motherboard.  Ground yourself.  Also, if your new EPROM originally came with a daughterboard (piggy-back) attached to it, it is required to keep this.  The daughterboard prevents easy copying of chips.  The RSC (Aprilia EVO) chips and Factory Pro chips have these.  If you go back to stock chip, you must remove the daughterboard from the ECU motherboard.