Is there a way to manually lower a convertible BMW's top?

We have a 2000 BMW Z3 and we just had the top replaced a few weeks ago. The other day, I tried to lower the top and pushing the button caused a big pile of nothing to happen. Obviously, we need to get this fixed, but. . .

It’s really pretty this weekend. I’d like to enjoy the benefits of a convertible. Is there any way to manually lower the top?

I can push it back about half way, but then it kind of just sticks (like, it goes back to where the motor would start pulling it back, then stays). I’ve Googled a bunch and found nothing. I tried calling the dealership and no one is answering.

Any ideas?

Thanks!

Found this, which is for a 328i, which may or may not be of help:

Here’s another page I found that may be useful if the first one doesn’t help. It deals with a Z3 convertible:

And another link about Z3 convertible tops:

Hope one of those helps!