Harbor Freight Manual Tire Changer for 275/40/ZR18 Corvette tires using General Purpose Tire Irons.

Using the Harbor Freight Manual Tire Changer for C5 Corvette Rear 275/40/ZR18 Tires.
Harbor Freight Manual Tire Changer # 69686 and 62317 $49.99, with 20% coupon $39.99.
Harbor Freight General Purpose Tire Iron # 93230 and 61603 $5.99 each, with 20% coupon $4.79.

The HFT Manual Tire Changer is completely capable of doing low profile larger tires. This video shows mounting, I have also used it for dismounting low profiles to change pressure sensors and tires. Works great! The tire changer is not bolted to the floor in the video to show it can be done, although securing it to the floor is recommended.

What you'll need in addition is listed below.
One piece of wood with a hole bored in it.
One 2" deep by 3" wide C Clamp (or something close).
One piece of rubber matt to protect the rim from the C clamp.
Dish soap....borrow some from the kitchen!
Compressed air...free...air compressor...buy one!
Two hands...maybe not..actually might be one hand capable.
Gloves...nitrile coated...wear some!
Safety glasses...$1.29...buy them and wear them!
Motivation to change the tire yourself because the shop screwed up your expensive nice wheels!!!