I would summarize the memo in one (long) line as:

"Non-discriminatory [against men] ways to increase women's representation in tech include making engineering people-oriented (rather than systems-oriented), disincentivizing competition, endorsing part-time work, and making it socially acceptable for men to leave tech and leadership for traditionally feminine roles, but a meaningful application of these strategies would prevent driven employees (mostly men) from working extra hours or taking extra stress, which would have disastrous consequences for Google's success."