If you can't pull or push it, but have access to metalworking tools or a machine shop, here is another thought. Get a piece of pipe that has an inner diameter that is only slightly larger than the outer diameter of your existing pipe (scrap metal dealers may have something like this). It only need to be about an 8 to 12 inch piece - this will slide over your existing pole. Get another piece about the same length (at least longer than the collar that goes around the pole on your dish) but that is the same diameter as your existing pole. Also get a piece of thick plate steel (at least 3/8 inch, but thicker would be better) that is 3 or 4 inches larger than the diameter of the pipe in one direction and maybe double that in the other. The idea is that you cut the plate steel into two triangular pieces that will each sit on the end of one of the pieces of pipe. You may need to take them to a machine shop to get this done. But what you want is two identical triangular pieces, that will have holes drilled in the exact same position in each of the points. Then when the triangular pieces are bolted together, you should be able to set them on the end of the larger piece of the pipe when it is standing vertically, and be able to loosen or tighten the nuts without any interference. So you don't want any of the holes too close to the pipes, that's why a bit of excess steel is better than too little. It would also be a really good idea to round off the points of the triangles so they don't impale anyone that happens to fall against them.
You also want to drill holes sideways into the larger pipe itself and thread those holes. For extra holding power put a nut on a threaded bolt, and then tighten the nut into the hole. Think about how many C-band satellite dishes are attached to the pole, with nuts welded to the collar that secure them from turning. You are basically trying to create a new collar for your existing pole. Then you weld the nuts to the pole (not the bolts, though!) and you weld the triangular plate steel to the ends of the pipes, one piece of steel on each piece of pipe, so each pipe has an open end and a closed end.
Then you stick bolts (nice big ones) or threaded rod through the triangles, as the flat ends of the triangles are facing each other. You stick a bolt through the triangle attached to the larger pipe, put a lockwasher and nut on it, and tighten it down, and do likewise on the other two points (note you are only going through the one triangle for this part). That is the part that will sit on the pole, where the dish is now. Then you put another nut on each bolt, and run it down the bolt an inch or two, and then slide the other triangle onto that, so that the two pieces of pipe are facing away from each other. That other pipe is what your dish will attach to. Finally you put another nut on the other side of the triangle on each of the three points. So each bolt will have three nuts on it, and I'd definitely use lockwashers also.
If you have done it right, you can temporarily lift the dish off the pole, slide this contraption onto the existing pole, then slide the dish onto the smaller pipe. Tighten down the dish and the use the three sets of upper nuts to get the dish level, raising or lowering each point as necessary. You can rotate the bottom part to re-aim your dish before locking it down to the pole. I know this may be a bit hard to visualize but unfortunately I don't have any drawing software and I'm not much of an artist anyway.
The most necessary thing is to make sure the welds are good and extremely strong - you don't want your dish breaking a weld and flying away in a windstorm! And also, you do want to round off those triangle points so no one loses an eye (or worse) if they happen to fall against it. This is just a concept, I assume no liability if something bad happens - it's up to YOU to make this safe for you and the people around you!