Popping the pistons out from the bottom is no big deal Ramon. The biggest trick you would have would be if you have a heavy ridge to get past. I dropped the pan on my diesel when I had the head off, popped the pistons to expect the rings and put them back in. You can "rent" the ring compressor from Autozone for nothing to do the job and they even have a ridge reamer if you need it. No need to pull the motor or the crank.