I have just bought Vegas pro 18 but the app is linked to an email that doesn't own the app and I just want to know how to change what email the app is linked to
Is that in the last few days? I ask only because the Humble Bundle Vegas Pro 18 offer apparently ended on 20 April - nearly 2 weeks ago.
If you purchased from HB during the HB offer, you'll likely need to contact HB to ensure that they issued with the correct serial number rather than a duplicated serial number that somebody else has already used.