Where can i find a manual on how to replace the brake line on a 02 chevy s10 xtreme?

I'm not aware of a particular Manual that specifically addresses Brake Line for your Specific Vehicle.
However I have replaced several "complete" and "partial" Brake Lines in my years of experience.
Specific/Pre-Contured Brake Lines for your Truck are available at most auto parts stores. Calt them for availability and prices.
However these are somewhat expensive. YOU CAN 'MAKE' YOUR OWN LINES!
Also available at these auto parts stores are two (2) tools you can buy.
1) A Brake Line Bending/Shaping Tool.
2) A Brake Line Cutting/Flaring Tool.
These tools are very easy (and fun) to use.
The auto parts stores carry "Straight" "Bulk" Brake Lines in different sizes (lenght and diameter). They also carry Brake Line "male" and "female" Brake Line Connectors. Make sure you purchase the correct diameter size Brake Line and the correct Connectors to fit these Brake Lines.
If the original Brake Line that you are replacing has viable (usable) sections and/or connectors you can use, then use them.
Take the old Brake Line off using a flare wrench.
Check your Brake Line Connectors to see if they will properly connect to your remain system.
Measure this piece with a material measuring tape (don't tell momma!). Measure the straight Brake Line and using the Brake Line Cutting Tool, cut the straight bulk Brake Line. Using the old Brake Line as a reference: use the Brake Line Bending Tool to shape the straight bulk Brake Line into the desired shape, matching as close as possible to the original Brake Line.
BEFORE USING THE BRAKE LINE FLARING TOOL:
Place the proper "male" or "female" connectors onto the line, FACING the proper directions.
Using the Brake Line Flaring Tool: Flare the ends of the Brake Line.
Connect the "new" Brake Line using the flare wrench.
Make sure you Bleed the entire Brake System.
Let me know if this helped, or if you have any additional information or questions. Feel free to contact me at FixYa.com!
ps: Make sure you clean, roll-up and put away that material measuring tape!!