One quick[ish] way to do it would be that after you've changed the hex values for the rotation, is to just go to your logos in TM, isolate each one with a 6w x 4h window, use Select All to "load" the sprites, then change the size of the window to 4w x 6h [making sure that the offset didn't change, I find it does that sometimes at random] use the rotate button to rotate your logo 90°, then click off in the empty space to "unload" the logo sprite and you're done.
Well, one anyway.
You'll need to repeat that a few more times.