In article , "RichardS"
lid says...
snip

2 posts now cleanly out of the ground (unfortunately with metposts still
attached, but I can sort that out later), a few more to go.

I worry that the posts will not be quite as stable now when the metposts are
hammered back in, but I think I'll hammer down some earth into the holes
before trying to re-sink the spikes with the new posts.

I may also have to buy a few new spikes - there is just no way that these
things are going to be voluntarily separated from the existing fenceposts!!!

Drill a big hole down the middle then chisel the rest out.