It is possible because a) it's not difficult and b) you're motivated.
My first suggestion would be to get your income and expenditure together in a format that's easy for you to work with. A spreadsheet, spending diary or - what I do - download MS Money and fill in all your transactions for several weeks. And that's everything including cash withdrawals, credit card transactions, Direct Debits, standing orders. Really understand where the money is coming from and where it's going to as your first step... even if it's painful.
Next I would look at all your regular outgoings, be brutal and decide if the item is necessary or a luxury. If it's a luxury, get rid of it. (Cars only depreciate and cost money to insure and maintain... if you can manage without, it's a luxury you can't afford) If it's a necessary expense, see if you can bring it down. Comparison sites are good for utility bills, insurance, broadband etc. If you can save £5/month here and £10/month there it quickly adds up.
A smaller budget for irregular outgoings like groceries, petrol, outings etc., is going to be on the cards. Again, £5 here and £10 there frees up spare cash. Takes effort and planning but that's what it takes.
Next step is to look at your debts and see what you can do to get them down. Overdrafts and CC's tend to cost the most % interest, followed by loans and then probably mortgage. If you have any spare money, use it to pay off the loan that is costing the biggest % as priority whilst keeping the others ticking over. If you can borrow the same money more cheaply (like your 0% card) consider that.
If you go through your income and outgoings in detail, budget closely and, despite all your efforts, the income simply doesn't stretch far enough then do talk to one of the free debt advisory services i.e. CCCS, CAB or National Debtline.
Good luck