Instructions to install paper feed roller and separation kit on HP Laser Jet 5L.
I want to replace my paper feed roller and separation kit on my
printer since it's not picking up one paper at a time.  If possible, I
need diagramatic and text instructions.  Thank you

Do you already have the roller and separation pad?  Is this a bottom
loading printer or does the paper load at the top and gravity feed?

A 196-page 5L service manual is at this link in PDF format:

http://www.computerfuchs.net/neu/pdf/hplaserjet5l_eng.pdf

Pages 110-114 describe how to remove and replace the separation pads
and subpads as well as components of the feed assemply, including the
paper feed roller.  To follow these instruction would require
referring to other parts of the manual as well.   This comprehensive
manual may be too cumbersome to use for your purposes, but the
information that you want appears to be there.