ZEN CART UPGRADE & GLITCHES FIXED

I'm looking for an experienced freelancer to upgrade my existing website's eCommerce platform from Zen Cart Version 1.5.x to its most recent version, as well as fix any glitches and errors associated with the old version. I have a detailed list of specific glitches that need to be addressed, so the successful candidate must be familiar with this type of work. Regarding the project completion deadline, I am flexible and can discuss timing in further detail. The glitch I need fixed ASAP is the UPS Shipping module. The old Zen Cart UPS shipping module stopped working.