When I did mine, I used OEM parts, so no welding involved.
I had it much "easier" since I removed the engine
But like I said, one side nut is blocked by front differential from the bottom so sway bar has to go and differential needed to be dropped a little.
That was probably the passenger side.
PS: When I think about it now, did you have the correct part ? Maybe it was from a different year ? It's hard to believe that you would need to modify the part to fit by drilling and welding. But if that was the correct part, then Anchor just simply sucks. Nothing worse when you are in the middle of the job, and get to the part just to find out that it does not exactly fit.