Usually these kits come with several sealed bottles. If your kit contains none resuspended bottles for all of your steps, it will definitively work. I have done it.

If the solutions are resuspended it might still work if the critical solution is still completely clear (not a little yellow). Good luck.

Thank you very much, indeed, Eric. That'll spare me some money.

If it's for research and you have appropriate positive and negative controls, just go ahead. If you are preparing materials for clinical use: don't even dare to think about it. By ignoring the expiry date, you are taking all responsibilities of the manufacturer.