I would NEVER EVER EVER EVER cut a opening into my car. If you drop the tank once second time is allot easier. Well is the same job but you have the experience.
A word of caution when dropping the tank, really be careful disconnecting the fuel filler pipe (actually that small hose between the tank and the filler pipe) as the hose is $100 and the filler pipe is $550. But that is not the bad news, the bad news is that all the money in this world won't get you any of the two. The parts are long time discontinued. Also be careful with the nylon fuel lines, don't kink them as is one piece all the way to the throttle body (in some situations).
Is always easy to handle a empty thank so make sure you drain it before releasing straps.