How to change the column text of an ALV in WD?

Hiya,

I have an ALV and it displays this in the column headings:

I'd like to change 'Name 1' to 'Name' and 'Boolean' to 'Selection', but I can't seem to figure out how to do this in the maze of all the classes and methods...

Could someone give me a few pointers please.

Thanks in advance!