Climax Axle width

[rson65]

Hello everyone,
I purchased a used Bachmann Spectrum Climax Model #25760. It says on the box that it is ON30. When I went to put it on the track it would not fit. The wheels are spaced to far apart to fit on the track. I have heard that the wheel spacing can be changed by spreading or closing up the gap of the wheels on the axles. Is this possible? If so how would I go about doing this? I am an aircraft mechanic and have been accused of being a bull  in a china shop at times, So I want to be easy with it. LOL