Park Recreation Help

Is it possible to edit the rides that are in a park after you've started working on it? (Even if you have to use a trainer) I'm working on Geauga Lake and forgot one of the most important ride types: The intamin impulse! Is it possible to make the map size larger also? If anyone has any good recreations of the parks rides or want to help build or test let me know.

Thanks[:)]

uhhh i dont think there is make room