I wrote and submitted my software patent application by myself and got Alice rejection (not completely unexpected). I contacted a patent lawyer to write claim amendments and he sent me contract and power of attorney forms to sign. I am comfortable with going with him but if we get final action rejection I want to switch back and continue persecution on my own. I just think it wouldn't worth all lawyer's fees. My concern: how difficult it would be to get my case back from the law firm and have POA reversed?
This would be very easy. The simplest would be to simply ask your patent attorney to withdraw his power of attorney.
You can also just file form AIA/81. Sign the form without appointing anyone to prosecute the application. This will have the effect of withdrawing the existing PoA.