This website will give you an idea of what needs changing to convert it to a C1:

http://www.trackjam.com/trackjam/lprdc1conv.htm

Trackjam sells full kits and parts for various 1/35 and 1/72 scale, highly recommended!



Images of the conversion kit (white resin parts) shown on an Italeri 1/35 Leopard kit:



Trackjam/Mapleleaf Models also includes decals



Photo of a really nicely done 1/35 Leopard C1 by Mark Innis



Photo of a really nicely done 1/35 Leopard C1 by Mark Innis

Note: All images in this specific post are courtesy of http://www.trackjam.com