its easy, try it!
Step 1: First,
Take the motor and pry the end cap off with a flat head screwdriver.
Step 2: Second,
Pull out the armature.
Step 3: Third,
Pull out the U" shaped piece of metal. (sorry about the crummy picture.)
Step 4: Fourth,
Pull out the magnets that are located on the sides of the inside of the motor shell.
Step 5: Fifth,
put the magnets back the way you took them out
Step 6: Sixth,
push the "U" shaped piece of metal back in
Step 7: Seventh,
put the armature in the way you took it out also.
Step 8: Eighth,
put the end cap back on
Step 9: Finally,
your done! hope you thought this was interesting.