My sister in law has a friend with cancer. She was asked by her friend to help her apply hair extensions to her friends short(but growing back)hair. I need to get some specific directions and/or tips on how it is done correctly and easily. Thanks.

I put hair extensions in a friend of mines hair. You want to do this very carefully here is two web site i found for you good luck i hope it helps!
Short Hair: Concealing Extensions On Short Hair
Hair Extensions The Safe Way
These were the best i could find!