I can't keep my weight steady, i fluctuate 40 pounds up and down, does it matter if i get breast implants removed at high or low weight?

No: But i would suggest that you do it at the low weight range.

Dr Fiala agreed

Stable Weight.: Generally, best to undergo elective breast surgery when you have achieved a long-term stable weight. Doing so will potentially increase the safety of the operation and allow you and your plastic surgeon to determine whether any additional surgery (for example breast lifting) will be beneficial at the time of breast implant removal. Avoidance of weight fluctuation will eliminate one variable...

Before implants?: What did your breasts do before implants and weight variations? Whereas some women's breasts change dramatically with weight alterations, others note little if any change. I would suggest that your breasts will experience similar changes with the implants and this may have implications for breast reduction, breast lift or other interventions.

Dr Tuma agreed

Most women: Will notice breast size fluctuations with that amount of weight change. If you remove them at your lowest weight, you will have the best idea of what your breasts will look like at their smallest, and most "deflated".