I recently had to replace shafts in my HMS Amazon after one developed a totally seized needle roller bearing.
First I made two thick neoprene pads to sandwich the hull, on its side, with long adjustable claps. This to protect detail which wasn't fitted when I originally mounted the shafts.
Then, using a fine pointed diamond-coated bit, I used the trusty Rotacraft (like a Dremmel) to carefully drill around the shaft like a dentists drill. Took out 3 mm all round the shaft, which includes the epoxy I had used to set the shafts in place. Not too much of a mess and the hole not too large.
Fitted two new regular 2mm shafts, set with epoxy as originally, then a bit of filler to smooth the hull profile.
Amazon runs very nicely again now, as you may have seen at Black park.