Looks like the stainless steel is rusted.how do you fix that.

SOURCE: rust stains appeared all over

If I understand your question, your stainless steel surfaces have rusted. Correct?
Contrary to popular belief, stainless steel CAN rust under the right circumstances.

I won't go into what may have caused this problem, but I will hopefully help you solve it and prevent future rusting.

Usually it is only surface rust and not deep pitting of the steel.
Surface rust can usually be removed with a product like Soft Scrub cleanser or liquid Meguiar's Car Cleaner Wax.

Apply a small amount of either product to a clean cloth and rub over the rust until it is removed.
Wait until the product dries and buff with a clean cloth.
If you have a brushed stainless steel surface, you will want to rub in the same direction of the "grain".

One benefit of the wax is that it will protect the surface from future rusting.
If the rust cannot be removed in this manner, a more aggressive approach is required. Do NOT use the following procedure if you have a smooth stainless steel surface, only if you have the brushed surface..

Use a non-metallic scuff pad, such as a 3M Green Scouring Pad and rub in the direction of the brushed stainless steel grain.
This process should remove all surface rust and even some minor scratches. You can use the pad dry or better yet, with a liquid wax as a lubricant.

Never use steel wool!
It will only leave small particles of steel imbedded in the surface. The condition will look worse when the particles themselves rust!

I cannot be held responsible for any damages that may occur from the above procedure. But, it has worked fine for me whenever I have implimented it on dozens of similar surfaces.

Good Luck!