I'm 56 years old, should I remove my breast implants before I'm too old?

As others have said, if there is no problem with the implants and you like your breast size and shape, then there is no reason to remove them.

Thank you for the question;  I am sure that there are many women in your situation who will benefit from the responses here. In my opinion, assuming you are healthy, your age is not a major factor. Again, assuming you are an overall good health, women much older than yourself are able to undergo elective breast surgery safely. What IS a factor however is that you feel that your breasts are too large:  based on these concerns, downsizing of breast implants or removal of breast implants seems to be indicated.   Of course, definitive advice would require in person evaluation, including physical examination and careful communication of your concern/goals. Ultimately, whether to undergo further downsizing or have the breast implants removed altogether will be a very personal decision that only you can make after careful consideration of your goals (as well as the pros/cons associated with each option).   In my practice, I encourage patients who feel that they may be pleased with the outcome of  breast implant removal surgery to be "implant free";  doing so will minimize the chances that additional surgery will be necessary in their lifetimes.   I ask these patients (who are undecided) to show me how "small" they are willing to (when it comes to breast size);  this careful communication helps patients make a decision whether to proceed with additional downsizing or to have the breast implants removed altogether.
 If you choose to proceed with downsizing surgery,  adjustment of the breast implant pockets (capsule adjustments) as well as additional breast lifting (revision of your previous breast lift) may be necessary to achieve the outcome you are looking for. Much will be dependent on your physical examination;  specifically, factors such as the amount of redundant skin and  quality of skin elasticity will be important.
 Generally speaking, the best online advice I can give to ladies who are considering revisionary (downsizing) breast augmentation surgery is:
1. Concentrate on choosing your plastic surgeon carefully. Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as “natural” or "down a cup size” or "C or D cup" etc means different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup size may also be inaccurate. 
3. Once you feel you have communicated your goals clearly, allow your chosen plastic surgeon to work with you in determining the best plan to achieve your goals.
I hope this helps. Best wishes with your decision-making at for an outcome that you will be pleased with long-term.