Grind as much weld as possible with a regular 4 1/2" angle grinder with a 1/4" disk.
Drill 1/8 inch holes around the diameter of the pin right through the center of the weld bead, that you can not easily grind.
That looks to be about 10 or so holes,,
You could drill the holes in less time than it would take to call the dozen weld shops that tell you they are accepting no new work.
Between grinding and drilling, then a few well placed swings with a BFH,,, the pin will pop right out.
AND, if you are not up to drilling, set the part on some saw horses,
get your welder, set at 160 amps or so, and grab some 3/32" 6011 welding rod.
Make sure there is nothing flammable under the saw horses,, and
run the 3/32" rod over the old weld bead.
The welding rod will cut the old weld nicer than an oxy-acetylene torch would, in that confined space.
Much faster, too,,
Wear high top boots, the old weld will flow right out, and head for the ground at a RAPID pace,,
You might even consider placing an old piece of plywood between your feet, and where the molten steel will be falling.
You wonder how I know this will work??
I am positive this will work, considering the number of times I tried to place a vertical weld,
only to have it fall right down into my boot!! 