[ITSv40]

Take both wiper arms off and remove the black plastic panel below the windscreen. Several screws which are obvious and remove the two drain pipes that hang down in the engine bay. Once the panel is off there are two drain tubes in the bottom of the scuttle - one each side - clean these out and clean the area around. Good idea to check the pollen filter as well. Replace the black plastic panel and clean the two drain tubes that were removed when removing the panel - these block at the bottom of the tube, so need a good clean out. Replace tubes on panel and wiper arms. Note there are four drain tubes in all.

Edit: just noticed you have a '58 plate. You need to post in the correct forum as this deals with V70 upto 1999. Your car will most probably be completely different.