Complex sentence: Jax goes to a storage unit to collect some old baby clothes and comes across a box of his father's stuff, in which he finds a "manifesto" outlining what the now-deceased founding member of SAMCRO hoped the club would become.
Split into simpler sentences: Jax goes to a storage unit to collect some old baby clothes. He comes across a box of his father's stuff, in which he finds a "manifesto" outlining what the now-deceased founding member of SAMCRO hoped the club would become.