First things first, cut out the dead wood. Alan Hutton and Charles N'Zogbia should both go. Charlie should fetch you around 6 million, Hutton can either be sold or go out on loan. Might also be an idea to get rid of Fabian Delph (whatever you can get for him) and Stephen Ireland (asking price).
That should give you a bit of money to play with. From there, I'd try signing Reo-Coker on a free, Wellington Nem for his 3.5 mil minimum fee release clause, and a left back. I choose Tsepo Masilela for the latter, but whatever. That should all be covered by the sale of N'Zogbia. Then, you'll have to find a left-sided midfielder of some description - perhaps Bernard or Thomas Drage - and you should be good to go, more or less.
If you want more money, Bent can usually be moved on for 20 million to Spurs or Chelsea, and Dunne can also be offloaded. I usually do this, but only cause I play with one striker. Then, you can use that money to buy a new centre-back and strengthen your team.