Get the FSM, Factory Service Manaual.
I buy Factory Service Manuals as a downloadable PDF on ebay. Here is one for $8:
https://www.ebay.com/itm/403169348821?mkcid=1&mkrid=711-53200-19255-0&siteid=0&customid=link&campid=&toolid=20001&mkevt=1
Honestly, after you get the FSM, you'll consider...