Steps:
un-screw the screws on your calculator,
this includes two on the bottom and one next to the
backup battery.

Use your flat screw drive to open the calculator.
Sliding it through the side gap of your calculator and
turning your screwdriver to pop it open.

Remove the anti-static foil paper by un-screwing the
two screws located at bottom you your calculator.

Un-screw the two screws that holds the LCD (screen) in
place, It's located at the top of the calculator.

Now you can see the whole motherborad of your calculator.
You should see three big IC chips. The one at the very left
is the ROM chip. The one in the middle is the S-RAM chip. and
The one at the very right (biggest one) is the Calculator's CPU (Z80)




Locate the "C9" capacitor, it's at the left side of the CPU. It
has the shape of a rectangle.

Now un-solder the "C9" capacitor, the easiest way to do this is
by melting the right side of the capacitor first, then quickly melt
the left side and quickly melt the right side again. (repeat this
process until the capacitor comes off)
*** Becareful! Don't burn the Wires connecting to the LCD Screen!!! ***

Now solder the NPO capacitor (0.1 pf) back to where "C9"
was located (it doesn't matter which side you solder it, it's not
a eletrolytic capacitor)

Just put all the parts back together then you're done! The
calculator is now about 4 times faster then regular TI-85!!!

How do I get NPO Capacitor?!?

EXTRA PLAN: Installing a SPEED SWITCH