How can I set a Welds CFrame?

I tried to set the CFrame of a Weld to a certain position, but every attempt I failed, I attempted many trys to find the CFrame part of a Weld (I dont know what it is to set the weld), how am I supposed to set it?

There are 2 CFrame properties of a Weld. They are C0 and C1.

C0 is the position of the weld, and C1 is the 'offset'. Learn more here.