3D Modelling and Texture Mapping correction for existing .fbx files

We are building a game, and we are using 3D model roads (I need a road to be cut in 1/3 but keep the outline sides) and to map textures properly for the original roads and thin roads. There are 4 platforms total. I am attaching one for now to see if you can do it: 1) You need to properly map the road (Road name polysurface1053) - I will need updated/new map textures for polysurface1053 2) Cut out this road (polysurface1053) into 1/3 of the size (keeping the outter line/ you will see that there is small stone separations - image attached). Apply proper texture to this road. Will need .fbx file and texture for it 3) adding a low poly (mobile friendly)/same type part of the model to the front and end (to the width, not length). Making the thin road look taller (this way when the user runs it does not seem like it is hanging in the air, giving it a feeling of floating island (This is a video of how game looks now - [login to view URL] and the screenshot shows how I want the road to look under - image file abstract ground ) End product - you will deliver 4 sets of platforms in .fbx files with textures (8 roads total - 4 regular size, and 4 one lane roads with proper adjusted texture maps with low poly/mobile friendly bottom to give a feel of floating islands)