I've had good results using Testors' 'Easy Lift-Off' to remove lettering on On30 scale Bachmann products.
It's designed to remove decals and stamped lettering without damaging plastic or paint.
I wet one side of a Q-tip in the solution then rub it on what I want to remove, after a while the lettering dissolves and the dry end can be used to mop up the remaining fluid.
If viewed under a light at JUST the right angle, you can see where the lettering used to be. Otherwise it appears like it came unlettered from the factory.
It's designed to remove decals and stamped lettering without damaging plastic or paint.
I wet one side of a Q-tip in the solution then rub it on what I want to remove, after a while the lettering dissolves and the dry end can be used to mop up the remaining fluid.
If viewed under a light at JUST the right angle, you can see where the lettering used to be. Otherwise it appears like it came unlettered from the factory.