How can I make my tank tracks thicker? Noticed my tank tracks on my tank model are thin, I need to thicken them up. I tried the solidify modifier but since the tracks have some holes/empty spaces in them it closed them. How can i make my track thicker?

I want to keep the polycount lower so if its possible to make it thicker without changing the actual geometry then that would be great. Basically i need to extrude the inside of the tracks.
Press Alt + S to access the shrink/fatten tool.
https://docs.blender.org/manual/en/2.80/modeling/meshes/editing/transform/shrink-fatten.html