Depending on how your cabinets in the front are done, you may need to take them out partially to access the fittings.
Depending on the dimensions of the tank, I have a smaller spare that I don't need anymore as it was replaced with a 42 gallon unit.
Baring that, PPL motorhomes sells these tanks for around $80 apiece, find one that fits in your space and gives you equal to or greater capacity, you're going to have to put in about the same amount of effort to just replace it, as you will to repair it if it is indeed punctured or cracked.