I used to run a plastics forming company for Point Of Sales displays
and bent all manner of plastics. For a bunch of bends then you will
need two lengths of square aluminum tubing with water fittings to flow
cooling water through. Space them about 1" apart. Then use a straight
electric heating element in between them and about 3/4" down below the
tube top surface.

Place the Lexan over the heating element and then gently lift an edge
ever few seconds to feel when it is soft enough. You may have to flip
it er to heat the other side, but do some test bends. Make the bend
then shut off the power an hold the material until it sets. You can
have a fan blowing on it after the heating element shuts off to speed
up the setting.

For a one-off item you an do what I did to make a chip guard for my
big mill. Run two strips of 2" masking tape about 3/4" apart either
side of where you want to bend. Use four or five thicknesses of tape.
Use a paint-stripping heat gun and move it up an down the bend area.
The masking tape will absorb some of the heat either side of the bend.
Again, you may want to flip it over to heat the other side. Don't get
too close with the heat gun as it will blister. Take your time, maybe
two three minutes to heat the Lexan through then make the bend. For my
guard I just leaned the Lexan up vertically then heated both sides,
made the bend then let it sit to cool down.

As another poster mentioned cyanoacrylate thread lockers will
crystallize the Lexan (many other plastics too) and it will fall
apart. Also do not try to bolt anything tightly through as that will
cause stress cracks over a few weeks and it too will fall apart. If
you have to bolt it, use thick soft rubber washers and minimal
tightening torque.

Good luck.

Dave