If the volume potentiometer (which connects to the volume knob) is 12 o'lock, the pins you should connect the positive terminals of the capacitors to, the pins are located at 4 o'clock and 8 o'clock. The silver thing in the photo is likely solder. Remember to discharge the caps before you dive into it. Usually, using the amp for more than twelve minutes (preferably longer), then turning it off, and leaving it off overnight should discharge the caps (mostly discharged when turning it off) fine. Still, check when your multimeter before really diving in. Off course, opening the amp up to do the Fitz mod will remove the anti-tampering stickers, thus voiding any warranty.
Here's a close-up pic from mine before I did the mod (see the cap arrangement in yellow). Just follow the two resistors alongside the caps in your picture and those caps indicated below.