The starting 11 is good enough and will only get better as they play more together.
Get rid of the shit on the bench, Chamakh, Park, Arshavin, DJ etc and replace them with proper players
That's it. Need to follow the Man Utd model - don't really need many star names just fill the squad with 20 solid players. We don't need any flashy signings, just get more players in like Arteta, Mertesacker and Santos...but in the right positions.