Don't just keep the PDF on your laptop. For the "active wave," you need to write. Print the exercise pages (lessons 51-100) or use a tablet with stylus support (iPad + GoodNotes works marvelously). The act of handwriting new vocabulary increases retention by 70%.
Before we go further, a crucial note on ethics. Assimil is a relatively small, independent publisher based in France. Piracy directly harms their ability to create new editions. Furthermore, a bootleg PDF without the 2020 audio is almost worthless—French pronunciation is non-negotiable. assimil french 2020 pdf exclusive
Do not open the PDF first. Listen to the lesson's audio (track 1) without looking at the French text. Try to catch 5 words. This trains your ear to parse natural French, not just read it. Don't just keep the PDF on your laptop