[wrenchnride247]

You have the right idea to practice, practice, practice first. As for welding the pans in you can stitch it, or plug it. Make sure your ground clamp is on bare metal, and area to be welded is bare metal (top and bottom)

Stitch welding involves doing short beads about an inch long and four to six inches apart. Careful around that factory tar board it burns easily

Plug welding involves drilling holes and filling hole with weld. If you want it to look like the factory spot welds you can grind the welds down and hit each one with a round blunt ended punch.

Regardless of which welding style used the front out side corners must be fully welded (you should remember this from grinding the old ones off) Then, when all welding is done use a good seam sealer on TOP and BOTTOM of the seams. This will get you rolling in the right direction, and back on the road for a long time.