To edit a symbol, just right click on the symbol (it has to be on the page somewhere, not in the symbol browser) and select Edit in Symbol Editor.

I can make a square, find a picture and label it appropriately. I don't know how to edit the picture - change colour or resize and add other picture into a symbol. For example I want to differentiate work e.g. group work, individual work, work in Yr4. So I want a standard picture for work then add another pic e.g. table, friends, computer etc. This was all so easy using boardmaker before we upgraded!