You can find the rules here:
http://pf2playtest.opengamingnetwork.com/
(this version does not include the updates 1.6.
or download them from Paizo
https://paizo.com/pathfinderplaytest#downloads
Just make sure you use the updated 1.6 version. They made some changes there. You can get a documant with all the updates from the paizo site here:
https://s3-us-west-2.amazonaws.com/paiz ... UE-1.6.zip