You can peel or slide some of the fins off the end of the heater pipe and put an elbow there. Add some short pieces of pipe and couplings to get it to fit exactly.
They do make a trim piece that fits over the two ends of the baseboards in the corner although you may have to look around for a piece that fits the make and model you have.
The good conscientious technician or serviceperson will carry extra oils and lubricants in case the new pump did not come with oil or the oil was accidentally spilled, so the service call can be completed without an extra visit.
just make the corner turn with raw copper cut piece into elbow from the left baseboard then another cut piece out of the elbow into the baseboard on the right..try never to elemenate the fins your taking away the heating rating