Please allow me to risk giving you some things to consider before doing a trigger job. If your P3AT is going to strictly be a range gun or maybe just a HD gun then sure go for lightening the trigger. If you're going to carry for SD then consider leaving the trigger as it comes from Kel-Tec. I can tell you from personal experience that should you ever have to draw and shoot your gun in a SD you will not feel the trigger pull weight at all. If you're involved in a trial (I do not have personal experience with a trial) as a result of a shooting your gun could be checked for modifications and that trigger job could work against you. Just some food for thought...
I won't purposely lighten the trigger pull on SD guns. I will work to smooth it out by polishing parts and even gently polishing the outside of a spring's coils. I won't cut or replace trigger or hammer springs with lighter springs---just in case.
Not to be a smart arse, but seriously, if you know someone that can lend you their P11 for a few days of snap-capping or better yet, range practice, you'll come to appreciate that P3AT trigger like you wouldn't believe. When I picked mine up after working out on my p11, I almost thought they had left the trigger spring out! I guess all I'm saying is, it's all relative, and the 380's trigger is relatively very, very nice.
There is no way to easily, significantly reduce the trigger pull on a P3AT without introducing the possibility of light strikes. Besides, the trigger pull is around 5 pounds, not at all bad for a double action pistol and in fact, better than many. Also, it will smooth up and lighten a bit the more you shoot it. If you want to hasten that process, you could polish the trigger bar. Other than that, I'd leave it alone.
I just picked up my p3at and haven't gotten it to the range yet, but after some snap cap drills, I'm very pleasantly surprised by the trigger. It is very long, but it is very smooth and breaks true. I wouldn't want to change the trigger pull at all for carry purposes.