Hi @clumbsy ,
Here is a link to the ifixit [guide|42286|Sony SLT Alpha-65V flash replacement] guide.
This should be of some help to gain access to the flash assembly so that it can be replaced.
Unfortunately I have been unable to find a replacement part online, (you may have better luck) but if you live in the USA you could try contacting this [https://www.ued.net/|supplier] and check if they have the part or may know where to get it from or even the part number would be of some help.