3bet the crap out of him vs his CO/BU opens. There's no way he can defend that much when he opens 90% from BU. It's just going to be impossible. I think he can only defend 25-30% at the very most (very tough to defend stuff like K7o vs a 3bet).
Use a super merged 3bet range. Maybe vs his BU i will 3bet him 25%, and if he starts 4betting a lot I just auto-jam 22+,AT+ or maybe you can add some more AX hands in your 5bet jamming range. You can also flat super wide vs his minraise and mix in a ton of checkraises.
Eventually he will be forced to cut down on his BU opening range. If he doesn't then you should be able to put a ton of pressure on him postflop by barreling a lot vs his floats.
Fold to cbet vs raise is really high too (60%+) so you should also exploit him.
For his CO opens, you should play fairly similarly to a typical TAG BU's opening range of 50% since he opens 47%.