how to add round bottom in infoboxs

[mtux]

hi , i want to add

1. round corner to bottom of my boxes like this :

http://osc3.template-help.com/osc_16407/

but i don't know how !

2. add , add to cart link in this month product like example .

3.add some discription on each product

4. move search box to top beside the link bar (i can do that but the border not remove!)

 

help me on this projects and after this project complete i'll realse it as a free template here .