You traded with someone ignorant about bicycles, otherwise you wouldn't have gotten the deal you did. Shortening a chain to make it easier to pedal???? Not in this universe.

In my opinion, the highest gear being too tough on flat ground is what a high gear is supposed to do. I only use the highest gear on any bike when going down hill or with a strong tail wind.

Let me guess, the part for the front brake lever is a turkey wing...

As far as lowering the gearing, replacing the chainwheels or freewheel are the only options to make pedaling easier, other than going with a lighter bike.