Reinstalling after a disk failure

I had a hard disk failure and lost my PSE and Lightroom. I rebuilt the disk and reinstalled them but when I tried to register, I got words to the effect that it was already registered on 2 computers and that was the limit.  Fine but it would appear that I have to be able to use the old PC (which is on the scrapheap) to deactivate the product before I can register the reload.

I have searched the forums and cannot find the answer. There are lots of references to 'live chat' but I can't find any way to do it!

I should be grateful if there is anyone out there who can tell me simply, how I can deactivate the products for my old (scrap) computer and reactivate them on my new one.

Many thanks in anticipation.

John