Stripping and refinishing is a ton of work, I'd do it to save good old woodwork (and often have), but for new stuff pulling it off and replacing it would be a lot easier and faster. Unless you have a lot more time and patience than money I'd get and install the correct material.

Donning Nomex suit-- You could experiment on some scrap with a topcoat of a colored finish to see if you could just add more finish to get to the color you want. Polyshades is a dirty word on this forum, but it or something like it might accomplish what you're trying to do without throwing out a lot of trim.

I guess I don't understand why it can't be done right the first time? Is this stuff pre-finished?

There may be a way to get there without stripping. You can add color with glazes or toners. The former is brushed or ragged on, the latter, usually sprayed. If you know what the existing finish is and can get a compatible top coat, one of these techniques might work, since you are going darker.

But I agree, if you can cut miters to length, it would be a lot less expense and time to remove and replace rather than strip and refinish.

going from a light stain to a dark stain is easy. i don't know what kind of finish is on now, but most can be re coated on top of new stain without a lot of drama. but you should find out the current top coat on these parts, so you know what to prep for. let me know.

using an extra dark walnut stain on top of reddish oak color will start you off to your espresso color.

"I guess I don't understand why it can't be done right the first time?"

Those are my thoughts.

Why go through the extra effort?

Wrong trim? Eat the loss if it matters to you. Or put up what you don't like and complain about it.