Any tips on fitting the US Car Tool Sub Frame connectors?

I paid a welder friend to install mine. B Body. He said it was relatively easy. He also ended up in the er with a hell of a rash from grinding off the undercoating. Protect yourself during the prep.
The welded in USCartool subframe were the single best upgrade ever for my ride. Solid on washboard roads more like a modern car. Put them in before other upgrades.