jace the mind sculptor. how it works

[Jiki]

how it works (jace the mind sculptor)?

[Kenji]

...The same as any other planeswalker?

So, what you're actually asking is, "how do planeswalkers work?" Here:

https://www.wizards.com/magic/tcg/ar.../planeswalkers

That breaks it down pretty clearly. If you read that article and still have questions, feel free to ask here, but the article should suffice.

[Jiki]

i mean how does last ability work

[DatAsh]

Then why didn't you ask that question to begin with?

Also, the question is pointless. You do exactly what the ability says. If you can't understand that, then you should read the rules of the game or have somebody you know teach you.

[Jiki]

i mean what does it mean to Exile all cards from target player's library, then that player shuffles his or her hand into his or her library

[DatAsh]

Exactly what it says. That player exiles all the cards from their library, then their hand becomes their new library.