sliding metal doors

Hope someone can help me. We have very heavy sliding doors to the outside. They are getting very hard to open and we need someone to check them. One is off the tract and the others need to be oiled or whatever to make them easier to open. Thanks for any help.

we have started using "junior" for various construction type things.
he is mary's husband who is the travel agent in chapala. his english is perfect. he even trimmed our queen palm using a scaffold among other things he has done for us.
cell#331-520-3054.