I'm sure it will be fine to just drain most of the fuel out and refill with the correct stuff. As already noted, with up to to 10% ethanol in ordinary fuel the system components need to be resistant anyway.
I mis-fuelled in this way about 10 years ago, when one supermarket chain was still selling E85 here in the UK (not sure you can get it anywhere now). The victim was my 67 Triumph Vitesse, running homemade EFI based on a Megasquirt ECU and 80's era junkyard injection hardware, mostly Bosch. It still ran - but very badly, being horribly lean. I limped it 10 miles home before hooking up the laptop upping the fuelling by 30%. This allowed it to run reasonably at light to moderate throttle but there wasn't enough fuel flow (pump or injectors, not sure which) for anymore, so I put it back how it was, drained the fuel out and put the right stuff in it. It was absolutely fine and the same hardware is still soldiering on 10 years later.
I used the surplus E85 in my ancient (early 80s) side-valve Honda mower. Took two seasons to get through it. The mower ran ok once started and warm, but needed a shot of carb cleaner to get it going initially. It was possible to start it without but needed patience and a strong arm! I made no adjustment to the mower whatever and it also is still in use. Very hardy machine!
E85 never took off here (UK) as it cost the same as straight petrol but you use a good 30% more......
Nick