There are no adjustments. Some folks will disassemble the triggers, stone the parts smooth, change the spring and wind up with a slightly smoother/lighter trigger pull.
Most competent gunsmiths can go a step farther and drill/tap the aluminum trigger housing for adjustment screws, change the spring, alter the trigger/sear engagement, etc. It's a bit tricky, but doable.
Or, for about $80, a replacement Timney adjustable trigger can be installed. More, if you have to pay someone to install it.