Used same database?

I have an old wordpress site at

What im trying to do is redesign the site (so everything would be fresh)
I guess Ill be doing the redesign over the next few weeks and want to know what to do,Should I copy the database (If I want to keep the posts and users) or should I just copy certain tables and create a new database (I think that this would be ideal)? but how do I make sure everything in the posts (media?) is transferred over once the redesign is good.

Why not you Import You data in New Site. WordPress having facilities to Export and Import.

He installed some dumb/not needed widgets and has the shopp plugin on the old site which I dont really care for, all I want to retain are the users and posts