Waste pipe elbow - replacing/repositioning?

[Chris993C4]

I've got a plastic waste pipe coming through a wall, immediately into a (40mm, grey, solvent welded) elbow. I'd like to reposition the elbow, so that the pipe continues onwards at a different angle.

However, the elbow is right up against the wall, so there is no spare pipe to play with:

      |
      |
      |####
----------########
pipe              #
----------#####    #
      |####    #   # elbow
      |        #   #
 wall |       ##   ##
      |       #     #

If I cut the elbow off completely, then the end of the pipe will be flush with the wall - are there internal fittings that could be used here?

Or, I could dremmel the elbow off, being careful to leave the protruding pipe as untouched as possible - although I can forsee problems sealing against a new elbow.