The clymer manual is also a good source. https://www.amazon.com/Clymer-Repair-Manual-BMW-70-96/dp/B000GZX312
You really need a service manual (unless you have an awful lot of experience ..you don't seem to ) Here's a link to a google docs download although if you're going to keep it I really recommend buying a physical copy ( just easier to use )
Google docs https://docs.google.com/document/d/1FTEOJGj-IVBX3vjZCenO6su2x6sZberepe0CtUMc3W0/mobilebasic
Amazon link https://www.amazon.com/Clymer-M502-3-Repair-Manual/dp/B000GZX312