Google mga guru (Barney Gaylord). He has a description of the process on his web site. This is an excellent site for all things MGA and British. I have done it and it is not terribly difficult provided you know how to weld. Be patient and check the door gaps ofte. Be prepared to install the doors and fenders MANY times to get the gaps straight. Do not do any final welding until you have done a complete final fitup of the doors and fenders including ALL hardware. Remember, resotrations of these cars is an exercise in compromise. Have a good day!
John