You can get a PDF copy on the Lexus website.
Copy of the relevant bits. Note the jump starting point is under the fuse box at the right of the engine bay.
Connect a positive jumper cable clamp to the exclusive jump starting
terminal on your vehicle.
Connect the clamp on the other end of the positive cable to the positive
(+) battery terminal on the second vehicle.
Connect a negative cable clamp to the negative (-) battery terminal on
the second vehicle.
Connect the clamp at the other end of the negative cable to a solid, stationary,
unpainted metallic point away from the exclusive jump starting
terminal and any moving parts.
Start the engine of the second vehicle. Increase the engine speed
slightly and maintain at that level for approximately 5 minutes to
recharge the 12-volt battery of your vehicle.
Open and close any of the doors of your vehicle with the power switch
off.
Maintain the engine speed of the second vehicle and start the hybrid
system of your vehicle by turning the power switch to ON mode.
Make sure the “READY” indicator comes on. If the indicator light
does not come on, contact any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Once the hybrid system has started, remove the jumper cables in the
exact reverse order from which they were connected.
Close the exclusive jump starting terminal cover, and reinstall the fuse
box cover to its original position.
Note that the hybrid system starting does not necessarily start the engine. You don't need to keep the donor car running once the hybrid system is started (ready light on).