paper stretching.......and then?

I'm a relatively new watercolour painter, not very good, but happy in my work. Recently I was told you absolutely must stretch the paper. This apparently is enshrined by law, as laid down in Magna Carta. I didn't know this and have never bothered before - and yes I do get a bit of cockling. But I'm a law abiding citizen and don't like to offend. So I've tried stretching. And yes it works. Soak the paper, tape it to the board, leave over night and yep, immaculatley smooth flat paper to work on. Wonderful - no more cockling for me. So far, so good. I should do this again. I painted my latest master piece. Then I have to take the painting off the board. Hang on - no-one told me about this bit. Nothing on the web, can't find any reference in my books........ Bearing in mind I am using the brown sticking paper as recomended at my art supplier, Do I ; a) peel off the sticking tape - ripping half the painting, and leaving most of the tape on the board? b) carefully cut out the painting - leaving all the tape and some of the paper stuck to the board? c) scrape the remaining paper/tape off with a small chisel? d)buy a new board every time I have to stretch a new sheet of paper? I'm sure I'm being thick, or missing a point here, but trying to get the tape off is is ruining my support board. So will someone with experiance of these things please tell me, how do you take the tape off again without destroying either the painting or the board, or both?? I would rather like to use the support again. Alternatively I could of course scrap the whole idea and carry on with unstreatched paper. At least I was happy in my ignorance.