In regards to Chelsea Manning, that bit is quite short:
"In addition, the broadened hacking conspiracy continues to allege that Assange conspired with Army Intelligence Analyst Chelsea Manning to crack a password hash to a classified U.S. Department of Defense computer. "
Forbes spent some time on this[1] and they believe that this really is the important part, this is the act that elevates Assange's actions to conspiracy. According to Forbes no password was ever derived from the hash and it never led to the collection of any documents.
[0]: https://www.justice.gov/opa/pr/wikileaks-founder-charged-sup...
[1]: https://www.forbes.com/sites/thomasbrewster/2019/04/16/unpac...