If there were writings by the Egyptians on the construction of the pyramids, they were lost. The first written surviving account we have on the construction of the pyramids was written by Herodotus, who claimed that slaves built the pyramids. Study of the pyramids themselves revealed that the construction teams were divided into units, and these units were assigned specialized tasks. The workers were conscripted in between the farming seasons to work on the pyramids.
As for the Mayans, if they too had writings on the construction of their pyramids, these too were lost. (The Spanish were very efficient in destroying Mayan writings.) The surviving documents were historical records and calendars.
As for Professor Hawking's belief, I think it was unfair to judge him without knowing where he got his information. He might have been reading books and scholarly papers about Human evolution, and formed his opinion based on these.