Social Security Repayment

I started taking social security when I was 62. Around $1800/mo.  I am now 71 and it has climbed to over $2000/mo. Had I waited until 70 to take my benefits, obviously it would have been significantly higher.  I am thinking about repaying SS the money that paid me up to age 70 and getting them to adjust check to the age 70 max rate. That means I will have to refund SS maybe $175,000 for those 8 years.  But I paid a lot of imcome tax on that money.  How in the world do I recoup all this? I can only do amended taxes for the past 5 years, but if I am understanding correctly I can't amend for SS repayment. Do I minus out my entire payment for each until I finally take the entire $175,000 reduction?