How would you change up a Franchise?

[KingBroly]

How would you change a Franchise while still maintaining some of the key elements that made the series great in the first place?

Example:
Making an Open World Super Mario game while still maintaining the platforming mechanics and awesome power ups (Fire Flower, Feather, Super Star, etc.)

[Nintend()\/\/|\|312]

I've always been interested in messing around with the setting of Zelda games. I think it would be interesting to see a modern day/futuristic/Victorian-era Zelda. The basic game mechanics could remain more-or-less the same (dungeons, puzzles, temples, combat) but one could maybe introduce different weapons or items based on the era. (Although I still feel that guns would be awkward in a Zelda game.)

Also, finding the entrances to temples in a modern day setting would be kind of fun if it involved searching through sewers, mines, subways and libraries. A little Indiana Jones-in' and I-never-knew-that-church-on-the-corner-was-actually-the-Temple-of-Time might be fun in my Zelda.