2007 yaris rust repair

[HDS]

I have to weld some rust on this yaris 2007 under the door. Don't know what to call the exact spot english, but part of the frame of the car that is under the door, faces the road and is quite exposed.

Anyway on the bottom of this car there is a plastic list held on by plastic buttons. This has to come off so I can remove the rusted part and weld in a new one.

Is there a trick to removing these in a non destructive way? I'd rather not just rip them off.

Picture to help visualize where it is
https://i.imgur.com/TqhoKov.png

IF someone could tell me the english name for this it'd be appreciated for future reference. Treshold I think is how it would translate, but it doesn't sound right.

[NYC-SE]

In English they are called "rocker panels"

[WeeYari]

In English they are called "rocker panels"

That is certainly what he is pointing at in the picture. However, rocker panels are not attached with plastic buttons. Makes me think he has side skirts on the vehicle. Would help if we could see his actual car.

[HDS]

Here's a photo of the plastic strip that's under the rocker panel, it's these plastic nubs I am wondering about. Can I remove them in a way that I can reuse them? They look to me like there's some trick in removing them rather than brute force.

https://i.imgur.com/Dzjv02D.png

[HDS]

I got them out using a knife and a small prybar, maybe half are reusable.

[ex-x-fire]

Dorman makes them, I think a box of them is cheap. Ill look for the number.

[ex-x-fire]

Dorman 961-379BX box of ten.