The first step is to carefully look at every account on your reports. They will either be:
(1) Open accounts
(2) Closed accounts that nonethless still occasionally send in a refreshed, updated record (even though nothing has changed). That may be as rarely as quarterly or even yearly.
(3) Closed accounts that have not reported to the bureaus for the last 14 months.
You can ignore #3 but in the case of the other two you should reach out to all of the creditors and make sure they have your current address.
The reason you are doing this is that you don't want to get addresses removed from the CRA report only to find that the addresses reappear when a creditor reports with the old address.
Two months after you have confirmed that all creditors have your current address, go through your report and circle every address you want deleted. Be sure that you have two addresses that you leave undisputed. Those would be your current address and your last address. CRAs often require that you have those.
Then just dispute all of those old addresses. Stay on message which is to simply say "this address is incorrect -- please delete." Don't get roped into a conversation about whether those addreses might have been correct at one time, and certainly do not affirm in a phone conversation with the CRA or in writing that any address might have once been correct. Just state simply (repeatedly if needed) that the address is incorrect.
CRAs have a legal responsibility to investigate anything you claim is incorrect -- and if they can't get a creditor to respond and affirm that the datum is correct, they have to delete it. With addresses this works out to deleting anything you claim is incorrect, since there won't be a current creditor that will affirm the correctness of that ancient address. That was my experience anyway when I get all my old addresses deleted. I also got employment info deleted and cell phone numbers deleted.
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