Greetings!
Unfortunately, there is no way to change the main account in a Cross Save setup without deactivating first. You'll have to deactivate Cross Save, wait the 90 days, then re-activate it selecting the correct platform as your main platform. [quote]If the incorrect set of characters have been set as the active Cross Save players will need to disable Cross Save, wait the full 90 day deactivation period, and re-enable Cross Save with the correct account set as active.[/quote] via the [url=https://help.bungie.net/hc/en-us/articles/360049498031-Destiny-2-Cross-Save-Guide]Destiny 2: Cross Save Guide[/url].
That's f'd cause I cannot deactivate due to buying silver... The cross-save function isn't very user-friendly imho and they should make a function to change back with in the first idk hour or so to prevent mistakes like this from happening... so now I won't be able to play my characters because of a not so user-friendly function. I don't mind having to wait 90 days to set up the cross-save, but not being able to rectify a mistake needs to be addressed.