If you use text links, all you have to do is change the tracking ID from yours to the buyer's through find & replace in the wordpress database. It would be best if you copy the product images onto your hard drive and upload them manually to each blog post too. All Amazon widgets would have to be created by your buyer within their own account interface.
If you are using an Amazon store script -- created within your account, then the buyer would have to create their own store -- the IDs cannot be changed out.
If you are using an Amazon wordpress plugin, which most require an Amazon tracking ID, an Amazon Web Services Access Key, & an Amazon Secret Key, your buyer would have to provide their own ID/Keys & you can find yours & replace it with theirs within the wordpress database.
hth