Well my man, it can only be done for real in scasm, and that's quite a leap for a conversion rook. You have to convert the mdl to a scasm file and edit it internally in text form. The good news is that the tanks are animated in the FS9 mdl, making them easy to identify in scasm code and disable. Because they're animated parts, disabling also kills them visually.
Another commonly used "external" approach is to try repainting the texture that colors the tanks with an alpha channel that renders them invisible. It works OK in most cases, but you still see the shadows on the ground in screenies and sometimes the invisible material of the tanks still interferes with mounted stores on the wings. I prefer the more complex scasm approach for a clean break from the tanks. Either way its not something that can be done with a simple 1-2-3 tip.
Not to digress, but your comments regarding the vet Jap pilot's viewpoint makes me wonder more about how their impressions of the Bearcat would have shaked out had they faced it also. In performance, it was as good as or even better than the Mustang by some accounts.