Of course you can. Whether or not they get a fee will ultimately depend on whether or not you win you claim, if you get a new lawyer and what the Judge decides (since they approve fees). Before you go down this route, have a heart to heart with your lawyer and then think about it for 24 hours before doing anything. If you decide to fire your attorney, you will then need to find a new lawyer or represent yourself (which I don't recommend). Keep in mind that you can always reject the offer and continue to pursue your claim with your current lawyer ...
You are certainly entitled to fire your lawyer, but you should think about the decision carefully. Your lawyer cannot accept the settlement without you. You should discuss your concerns with the lawyer and go over the reasons why he is recommending that you accept the settlement. If you decide to reject the offer, and he does not want to continue to represent you, then you can seek another attorney. If he will continue to represent you, then he will have every interest in making sure that your claim is successful.
If you choose to fire him at this point, he may continue to be entitled to a fee based on the value of the work which he has done to this point, but that fee must be approved by a judge. This area of the law is very complicated, and would be an issue to discuss with your new lawyer. You should definitely not try to go this alone.
This article might help you make a decision about whether to settle:
Generally, you may terminate a fee agreement with an attorney, but depending on the language of the agreement, you could be liable for costs of litigation. Also, when you terminate a fee agreement after an offer has been made, your attorney may have a claim to future attorney fees that your second attorney would have to share with the first.