how to pull low gear apart?i lost low gear…

was pulling someone out and it popped like it came out of gear…but now it has now low gear,still had high and reverse…trans is apart and no teeth are broken and really clean inside…in the manual it shows all the parts but doesn’t tell you have to pull low/high apart….is it possible there is something broke inside that gear assembly to make me lose low???

thanks for any help

plan to buy another trans and fix this one…don’t see me pulling on anyone again..winch only.