Adding points to polygon/puddle shapes?

[Nibbler]

Hey guys. I want to edit the shape of a puddle floor I've put in one of my maps, but the only way I can get the shape I want is by adding a new point into the object. I can't see an option for it. Does anyone know if it's possible, or would I need to delete and reapply that piece of flooring? It's no biggie if that's the only way, but I figure it's best that I find out now on one that I can edit easily.

[= WEMO =]

Easy peasy this one .......

Click the object in the list and select edit - the points will appear.
Right click the point select duplicate/remove as appropriate.
When finished click OK (or press Enter) to complete the shape.