They are the wide caterpillar tracks and must be nylon, except for the steel pads on each cleat (4 across each one). On the inside of both tracks, there is a more visible 'head'. so I think I'll try taking them off if I have to and hammering a pin or two out that way on the opposite side (outside of the tracks).
But first I would have to take the whole track off in order to do that properly I think, which wouldn't be too difficult at this stage.
First however, I should mention that both tracks came fairly loose in a quick amount of time - the front wheels (sprocket wheel) move or are loose so I might have to go inside to check if I can tighten it but I'm pretty sure that that's where the gears and motors are, if it's like the HL Sherman 7.0 I have. I just have to examine it thoroughly first and find a piece of foam to turn it upside down which of course would make the job easier.