Welcome,
1. i have 4 texture for 4 side of the wall. How do i achieve this?
If you count the top and the bottom of a wall, you could even wonder how to set the 6 sides of a wall! 
But I guess you want to change only the vertical parts. As Sweet Home 3D offers to change only the left, right and top sides, you'll have to create very thin walls that you put at each end of the main wall.
2. how do i donate a small token to this cause ? good job on this. impressive.
Thanks. 
You can use the Donate button found at the bottom of each page, or go to the Donate page.
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Emmanuel Puybaret, Sweet Home 3D creator
