How hard is it to replace a door frame and door?

[JamesW84]

If this is a pole barn (6x6's), I see no reason to replace the whole stud. I'd simply cut the bottom of that stud off (and the board in front of it) and slap in a ft or so of treated. You might have to pull the metal loose a bit, but that's better than removing it all.

The metal below the door is probably just there to make it look better. I would think it would be fine if overlapped correctly. At the very least, the J channel around the door should overlap the metal below it (not sure they left enough there to be able to cover all of the J channel with the longer top piece). The J channel covers the cut metal edges to make it look better. I used brickmold (normal door trim) and put a J channel over the top piece to direct water away.

I had my floor poured with a slope at the doors and since I have a foundation stem wall higher than the floor, I chose to not install a threshhold at all; doesn't look like you have that option.

 

[FTG-05]

That siding in front of the threshold is bad news. It's funneling water behind it, and keeping it from ever drying out. Ideally you want a threshold that extends above your step and have the step slope away from the building slightly.

See the first pic, post #32:

If the new one looks like that - it shouldn't be a problem, yes?

Here's the pic again for convenience:

 

[MikeF2316]

See the first pic, post #32:

If the new one looks like that - it shouldn't be a problem, yes?

Here's the pic again for convenience:

You don't want anything that water can get behind and not dry out. Ideally you'd want to prevent water from getting behind that siding. It's not as important when the threshold isn't wood, of course, but even with concrete or composite it's still desirable for that to dry out.

If that were mine, I'd take that piece out.