What user information do you want to transfer to your new website?

just so they dont have to sign up again just user info

In this case, you can export ow_base_user and then remove users, you don't want to transfer, from the sql file itself. However all transferred users will have to restore their passwords as the password have been hashed on the old website. 

Thanks ross

what plugin will ask them to restore their passwords

Not  a plugin, they have to click on forgot password link and reset a password on a new website

can someone explain a bit more on this? I'm a bit lost on how to do this.

you can move your users from one oxwall site to another by using CSV import/export plugins. They can be found in the store. However you'll be able to transfer only common data, like username, age, sex, no photos or any other user content.