I have an extra layer of skin on my left eyelid. What are my options to change it?

The muscle insertion on the upper eyelid skin is asymmetrical creating a double fold on the left side and a single fold on the right side. More photos are required to determine whether or not a single left-sided upper blepharoplasty skin removal only will be of any benefit.

It looks like you have 2 folds on the upper eyelid.  This can be caused by the way the muscle inserts onto the eyelid itself.  I recommend finding a board certified plastic surgeon to have an exam in person.  You can talk about your options.  Typically blepharoplasty, or eyelid surgery, is a good solution.  Your surgeon will discuss with you if anything else needs to be done during that surgery to correct the appearance.  Good luck!