As soon as you know you have a potential issue with paying your attorney's fees you should tell your lawyer. Many lawyers will attempt to work out a payment plan that works for you under your new circumstances, but some will want to get out of your case if they cannot be paid the agreed upon fee. If you do need to change lawyers it is better to do so earlier rather than later in a case. It will not do you any good to keep your problems a secret from your lawyer as they are like any other professional and have legal rights to be paid the agreed amount for work done.