Hello Ponury !
Using the module SOFiMSHA for deletion you simply use the DEL TYPE FROM TO INC .... method.
If you know how to use it for nodes I wonder why you do not know how to use it for beams
DEL TYPE BEAM FROM 1 TO 2 INC 1 e.g. to delete BEAM elements 1 and 2 (if existing).
For a redefinition you use a SYST REST and additionally CTRL REST 2 before you start to redefine.
Please refer to the handbook what can be redefined and can not. Otherwise you may delete and define newly.