I made a website time ago. Raw php with SQL. Now I am doing a new version with CakePHP, this implies a lot of conventions that I want to follow, that is, I'd like to keep things the cakePHP way as much as possible.

But:

There is a users table that I am trying to split into two new ones on the new version, adding fields and dividing user identification fields and usage statistics fields, I am still looking for the best way to do this easy, this is not the main question but any help will be appreciated. The table name is different to adjust to convention, and fields have changed. I still have to do some research of this.

The old site used sha1() to hash passwords and I want to know if there is any chance of keeping the records without making all the users register again. 

I found some cracking tips to do it faster than brute force. Well, they say they are faster, but I have about 1000 users. Besides, I don't think it's legal nor ethical to crack my users passwords to make my work easier. So cracking seems to be out of the question.

I thought of just copying the records as they are and set a "reset password" for them, so they can just log in again with a code sent to the email they provided when registering. This is not a very bad option, but I'd like to do it only if there's no other way.

Well, is there a way of doing this?