Switch primary cardholder?

[zzyss]

I have complimentary Altitude Black from a loan I have with Westpac. The loan is in joint names but obviously the credit card has to have a primary cardholder, which is currently me. I'd like to switch this to my wife (pretty much just so I can get the complimentary Priority Pass in her name, since I already have one with Citibank Signature.)

Has anybody tried this before? Any gotchas?