There is no chance of selling players. You need £500k. But even selling your whole squad at this point it would be difficult to raise this amount of money. Why? because whilst the club was solvant some players would be worth over 100k in terms of contracts. Now you have no money and insolvancy beckons, no club will offer money for a player they can get as a free agent in a few weeks.
If you had a player high in demand you may get something for them as clubs may compete with each other to secure their services.
In the end once the club goes bust, the players are no longer receiving a wage and so the contract is null and void and they can walk.
It's a shocking state of affairs and one that other clubs should take notice off, you can't run a business of loans and overdrafts. In the end income has to level with expenditure.