I tell people to take apart an ancient junk switching supply wall wart with a hammer and unwrap a winding from the transformer inside. That gives easy access to a small bit of enameled copper wire. They will need to be extreme about scraping the enamel to get to the copper. It is also a good idea to use a lighter to heat the enamel and scrape some more. Then they can wrap the exposed copper part around something like that transistor lead a dozen or more times like it is an old wire wrap job. If you can locate two such locations where a lead with an air gap exists, it is possible to make that connection.