I need to replace the battery but it is different from other cars, how do I do it?
First, two people responded to your post already: http://community.cartalk.com/posts/list/2149941.page
Bookmark it or something so that you can find it again.
Second, if you have to ask I’d say to just have someone do it, especially b/c (as you’ll see in the other post) sometimes certain precautions have to be taken. For certain years of this van I do know that taking out the battery power will cause issue (certainly '99 & prior). Many auto parts chains will install a battery for you if you’re buying it from them. But I’d just have a local mechanic do it.
If you really want to do it either look under the hood & figure it out (its not different from other cars - its just less accessible and you have to move stuff out of the way) or buy a repair manual at an auto parts store for $20