Easily? Swap out for a Kitty.
Getting the LEDs to light up with the button presses isn’t hard really, but would require soldering. If you take a peek at the labelling on the LED board in your TE, you should be able to easily identify the pins on the ribbon cables that go with what button; those eight are all ??Button, Like blahblahRT, blahblahLB, blahblahX, etc.
For each one of those, connect one leg of a resistor (1k ohm is a safe bet, and I think what I use on the Kitty) to that ribbon cable pin.
Connect the other leg of the resistor to a diode (N4148 are cheap and can still be bought at Radio Shack), specifically the leg that does NOT have the band on that end.
Connect the other leg of the diode (the end with the band) to your signal line for that button.
So in ascii art:
(blahblahRT pin on LED board)---------(resistor)------(diode)|----RT signal
That RT signal is the same one you also have going to the Chimp for that button.
Doing Guide is a bit different. You could do the same type of thing with the four guide LEDs and the four directions, but you couldn’t make ‘up’ be both top LEDs, and only one LED for diagonals without some additional complicated hardware.