there is no manual, Advance Adapter and James Duff both had a "guide" you could read that covers the basics, but every conversion is different so research is your best friend
There are COUNTLESS small block ford V8 conversions into Rangers/Explorer's online, a few very good ones on this site!
You need to start with a few basic questions
What transfer case am I going to use?
What transmission will work with that t case and with my truck/needs?
What V8 will bolt to that transmission and what computer will work with the whole drivetrain?
This will determine what you need as far as parts.
Plan a budget and a time line, then DOUBLE IT
TAKE NOTES, take pictures, and know what you are getting into before you tear anything down