What is involved in converting SMF 1.1.11 to vBulletin 4.0
 

I am currently running SMF 1.1.11 and have just started the forum so not a lot of members or posts, 1493 Posts in 387 Topics by 67 Members.

I am wanting to get vBulletin 4.0 and wonder how much trouble it is to convert what I have now to it.