Here is a user submitted YouTube video on how to install a throttle body spacer on a 4-cylinder Camry.
How to video on installing a 4-cylinder GGP Throttle Body Spacer (2:08 to 5:50 is where the install happens)You’ll see that you first take off the intake, then unbolt the throttle body from the intake manifold. Once you have the throttle body off, you’ll have the option of doing a coolant bypass. If you decide to take the throttle body all the way off you will spill some coolant, but it will not be much. Now, get the GGP Throttle Body Spacer and orient it to where the o-ring is facing the smooth side of the throttle body. Line up the holes and put a bolt all the way through. Now with your bolt through, line the spacer and throttle body up against the intake manifold and start to thread your bolt in. Make sure that the o-ring is still properly seated in its groove, then insert the other 2 bolts and tighten all 3 down. Once tight, install your air intake and turn your car on and make sure you didn’t leave any hoses off that might be causing a vacuum leak. If all is good, go for a test drive and feel the lack of throttle lag and your newfound power!