Edna was right and An uncomfortable Truth are very easy to get.
For Edna was right you have to be in young Emmett's lab. You have to click the pile of mind maps a couple of times till Emmet comments that 90 percent of Hill Valley are Hooligans. Bam done.
For An uncomfortable Truth you get to the point that Emmett pulls out the ring and says he's going to propose to Edna. You then interact with him and go through the dialog options. Then Bam you have the other trophy.