devices linked to my apple ID

When I go in the iCloud Drive section apple is telling me I have 3 iPhones which will not be able to use iCloud Drive unless I upgrade them. The fact is I have only 1 iphone .. The 3 they say are other 3 which may be my old phones.. How do I remove the devices from my Apple ID, I had done it before but now I can't recollect, searching the web isn't helping..