Help with making a (simple) mesh

[Andyno]

Hi there.

I'm trying to make my own mesh in Blender, and I don't know what to do. Let's say I start with something like this (a tunnel kit piece)...

http://img513.imageshack.us/img513/4783/uhts.jpg

... and I want to achieve this (a curved tunnel)...

 

http://img826.imageshack.us/img826/3056/4j8z.jpg

 

Looks pretty simple task but I'm really desperate how to make such thing. Note that I got fully textured piece, and I also want to make

it snappable (like original meshes in GECK).

 

Please help somebody.

A.