I have one gathering dust in the former workout room downstairs. Neither one of us is physically capable of carrying it upstairs and out for recycling! We will have to sell the house to someone healthier and they can deal with it. 
Wherever someone lives, their county solid waste management district should have instructions for disposal. You might be able to take it to their facility, or you might have to wait for an annual household hazmat day.
Speed comes from what you put behind you. - Judi Ketteler