Old & New Domain

Redirection from the ols one to new One.....

[experienced]

Hi,

One of the site got dropped from G and now i am planning to shift this on the new domain with the 50% same content of the old site.

1 - Do i need to delete old site from the server or i can put robots.txt for G Bot...?

2 - If i delete the old site and make a 301 redirection for new domain, is there any problem for G...?

3 - Should i change the server for new domain or i can place the site on the same server...?

Thanks
Exp...